Rendering bug in Bing Maps MapPolyline on WP7 if zoomed out?

Question

I'm having some trouble with MapPolyline. It somehow renders a gps trace incorrectly if zoomed out.

At a low mapControl.ZoomLevel (eg 9) some lines/edges are still drawn but they shouldn't. Here are some screenshots to demonstrate the odd behavior.

http://img403.imageshack.us/g/capture4jz.png/

Image Description:

1. The first image is zoomed out (ZoomLevel = 9) (pay attention to the blue MapPolyline)
2. Second image is zoomed in a little (the MapPolyline is still the same same -> incorrect)
3. Third image is again zoomed in further (however the MapPolyline looks still very similar)
4. Last Image: This is what the actual gps trace looks like.

So the MapPolyline is drawing the gps trace incorrectly if map is zoomed out. It seems that it stops scaling at some point and stays all the same at lower ZoomLevels (9 - 15 == zooming out)

Maybe I did something wrong? Can someone tell me how to fix this? Some workaround?

Here is a simple test app to demonstrate this odd behavior (this behavior is the same on the device and simulator):

MainPage.xaml

    <!--ContentPanel - place additional content here-->
    <Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0" >
        <my:Map x:Name="mapControl" Margin="8" CredentialsProvider="{Binding CredentialsProvider}">
            <my:MapLayer>
                <my:MapPolyline x:Name="mapPolyline" 
                                Stroke="#FF2C76B7"
           Opacity="0.85"
        StrokeThickness="6" />
            </my:MapLayer>
        </my:Map>
        <Button Content="+" HorizontalAlignment="Left"  Height="86" VerticalAlignment="Bottom" Margin="108,0,0,51" Width="95" Name="zoomInButton"  Click="zoomInButton_Click" />
        <Button Content="-" HorizontalAlignment="Right" Height="86" VerticalAlignment="Bottom" Margin="0,0,101,51" Width="98" Name="zoomOutButton" Click="zoomOutButton_Click" />
    </Grid>

MainPage.xaml.cs

    // Constructor
    public MainPage()
    {
        InitializeComponent();

        this.DataContext = this;

        // load an actual trace
        var loadedTrace = LoadCarDrive();

        var locations = new LocationCollection();
        foreach (var item in loadedTrace)
        {
            locations.Add(item.Location);
        }

        mapPolyline.Locations = locations;

        // zoom to center
        mapControl.SetView(LocationRect.CreateLocationRect(locations));
        mapControl.ZoomLevel = 9;
    }

    private void zoomInButton_Click(object sender, RoutedEventArgs e)
    {
        mapControl.ZoomLevel += 1;
        Debug.WriteLine(mapControl.ZoomLevel);
    }

    private void zoomOutButton_Click(object sender, RoutedEventArgs e)
    {
        mapControl.ZoomLevel -= 1;
        Debug.WriteLine(mapControl.ZoomLevel);
    }

    #region Car Drive Trace
    public List<GeoPosition<GeoCoordinate>> LoadCarDrive()
    {
        return new List<GeoPosition<GeoCoordinate>>() {
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315405647110000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24879119, 14.30983157, 264.5, 7, 8, 0, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315405667080000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24881212, 14.30975438, 266.25, 9, 8, 3.08515646975006, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315405686990000, TimeSpan.FromHours(1)), new GeoCoordinate(48.2488539, 14.30977517, 264.450002034505, 9, 8, 2.7708502915673, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315405707010000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24888582, 14.30973458, 264.833329942491, 7, 6, 2.622272942855, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315405727010000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24890673, 14.30970928, 264.027773256655, 7, 6, 2.09121417243467, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315405747020000, TimeSpan.FromHours(1)), new GeoCoordinate(48.2489299, 14.30967342, 263.053696997372, 7, 6, 1.89013767966395, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315405767030000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24893927, 14.30963082, 262.293819348999, 7, 6, 1.66950420129036, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315405787040000, TimeSpan.FromHours(1)), new GeoCoordinate(48.2489513, 14.30961666, 260.815840816629, 7, 6, 1.45526477188896, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315405807090000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24897547, 14.30958534, 260.136549319532, 7, 6, 1.42904734840548, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315405827120000, TimeSpan.FromHours(1)), new GeoCoordinate(48.2490056, 14.30956493, 259.084125976376, 7, 4, 1.48926924922331, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315405847120000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24901793, 14.30954465, 258.240225098636, 7, 4, 1.8838781127322, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315405927280000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24901616, 14.30950247, 257.208112955994, 7, 6, 1.42209719840891, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315405947300000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24902166, 14.30943419, 256.616110650371, 9, 6, 1.37894394353935, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315405967320000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24902592, 14.30939502, 256.30807656996, 12, 6, 1.19195039763596, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315405987320000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24906708, 14.30934571, 256.508064441282, 7, 6, 2.04223380763222, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315406007340000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24907986, 14.30932245, 256.405378302576, 7, 6, 2.21050803017023, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315406027360000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24908171, 14.30927428, 256.371151650296, 9, 6, 2.11644554209566, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315406067370000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24906849, 14.30929253, 256.325514053301, 7, 6, 1.30317650495332, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315406107390000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24908503, 14.3092208, 255.065555234533, 9, 8, 1.03139622772203, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315406147410000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24912105, 14.30913114, 253.697027164955, 17, 12, 1.28256512364723, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315406167450000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24913691, 14.30915501, 253.087527466496, 17, 12, 1.48256704150828, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315406207450000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24910669, 14.30913564, 252.394849509312, 26, 12, 1.45368860226716, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315406227460000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24905554, 14.30905891, 252.427454922925, 14, 12, 1.70982854209585, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315406247480000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24904891, 14.30902087, 252.407432776241, 14, 12, 2.32817436513961, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315406267490000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24903438, 14.30895531, 252.511633302066, 9, 8, 2.40899029224891, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315406307520000, TimeSpan.FromHours(1)), new GeoCoordinate(48.2490193, 14.30891254, 254.10635332493, 9, 8, 1.92159113286849, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315406327520000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24899752, 14.30886584, 255.33932684116, 9, 8, 1.38514001477141, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315406347530000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24899835, 14.30883893, 256.148560055363, 12, 8, 1.2548486272039, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315406387570000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24895525, 14.30878854, 257.595958229831, 9, 6, 1.33167435077218, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315406407570000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24894308, 14.30881919, 257.748172761731, 7, 6, 1.3437967879493, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315406427590000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24894424, 14.30879602, 258.148045698359, 7, 6, 1.40506752120999, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315406447590000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24897013, 14.3087708, 258.73206875102, 7, 6, 1.32722909233662, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315406507630000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24899411, 14.30871161, 258.393367414116, 7, 6, 1.19050981731556, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315406527630000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24900568, 14.30880985, 259.441816124056, 7, 6, 1.60071978622932, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315406587660000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24901868, 14.30875422, 258.645063213896, 7, 6, 1.42179922641885, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315406607680000, TimeSpan.FromHours(1)), new GeoCoordinate(48.2490225, 14.3087142, 258.128955710307, 9, 8, 1.6648361142989, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315406627690000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24899202, 14.30876327, 258.258006308068, 7, 6, 1.63091850786356, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315406647700000, TimeSpan.FromHours(1)), new GeoCoordinate(48.248999, 14.30873814, 256.795654006125, 7, 6, 1.69687386722371, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315406747760000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24898286, 14.30874518, 254.117882702387, 7, 6, 1.19924244305006, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315406787770000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24900199, 14.30874282, 252.40450816716, 7, 8, 0, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315406807800000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24901148, 14.30871393, 250.174130289849, 7, 12, 0.562022727939566, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315406847810000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24902338, 14.30869189, 247.292875416659, 12, 12, 0.674589842740374, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315406867820000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24902707, 14.30871843, 246.122333200998, 9, 12, 0.873256080158558, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315406907840000, TimeSpan.FromHours(1)), new GeoCoordinate(48.2490188, 14.30875003, 245.538406941563, 9, 12, 0.82098105319536, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315406967870000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24903988, 14.30876066, 246.520244679682, 14, 12, 0.75138387232891, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315406987880000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24901843, 14.30869998, 247.552885908253, 14, 12, 1.28196277976357, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315407007890000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24901495, 14.30869837, 247.82437482814, 12, 12, 1.07140934525889, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315407067930000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24893342, 14.30866289, 245.792420245464, 9, 8, 1.48298498088654, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315407087940000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24894735, 14.30866824, 243.872265024535, 9, 8, 0.870070550784878, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315407107950000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24895537, 14.3086449, 241.021559722161, 9, 12, 1.11347094540375, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315407147970000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24895027, 14.30862412, 238.031278984576, 12, 8, 0.773571842819805, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315407167980000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24894213, 14.30857577, 235.850946235579, 14, 12, 1.12116766217648, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315407188000000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24895591, 14.30851958, 233.260739705546, 19, 12, 1.27163333307808, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315407208000000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24895305, 14.30858254, 230.737230681547, 12, 8, 1.90409780733048, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315407228010000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24896214, 14.3085505, 228.832656795698, 14, 8, 1.72105403937988, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315407248030000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24891651, 14.30852579, 227.723297860253, 12, 12, 2.15635087285783, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315407268030000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24888497, 14.30851276, 226.018651551984, 14, 12, 1.91486801065635, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315407308050000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24889868, 14.3084777, 224.780651838584, 17, 12, 1.7239841715139, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315407328060000, TimeSpan.FromHours(1)), new GeoCoordinate(48.2489161, 14.3084672, 223.699763727846, 19, 12, 1.19438627085672, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315407348070000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24892424, 14.30845455, 222.860140556649, 14, 8, 0.846422498991796, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315407388110000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24897215, 14.30844792, 223.319966060326, 14, 8, 1.20716161411786, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315407428130000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24897508, 14.30842744, 224.160031469981, 19, 12, 0.932657766636434, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315407448150000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24899233, 14.30847249, 225.093328441092, 14, 12, 1.13484005811991, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315407488210000, TimeSpan.FromHours(1)), new GeoCoordinate(48.2489731, 14.30852733, 226.251119970358, 14, 12, 1.0108183931221, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315407508180000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24895873, 14.3085864, 226.881478734806, 12, 8, 1.4631129974199, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315407528190000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24897776, 14.30857073, 227.710866235055, 12, 8, 1.83969601940619, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315407548210000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24895268, 14.30856623, 228.097452392297, 14, 8, 1.80248844193688, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315407568210000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24899134, 14.30857573, 228.902770841279, 9, 8, 1.87871250563877, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315407588220000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24896963, 14.30857888, 229.666741077859, 12, 8, 1.57348661211614, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315407608230000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24897652, 14.30861496, 230.789833237369, 14, 8, 1.44588983852298, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315407648250000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24896462, 14.30855057, 232.685526806248, 12, 12, 1.62641254715026, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315407668260000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24897762, 14.30855976, 233.658453347872, 14, 12, 1.30362718600298, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315407708280000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24897772, 14.30853848, 235.647995419212, 7, 8, 1.09568972753188, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315407908300000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24897772, 14.30853848, 235.647995419212, 7, 8, 0, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315412290810000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24900281, 14.30853533, 238.398661578303, 7, 6, 0, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315412330830000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24916174, 14.30887975, 240.382221033677, 9, 8, 2.0845116247323, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315412370850000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24932241, 14.30944236, 242.993631606337, 9, 8, 5.21982023106023, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315412390860000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24939839, 14.30973055, 244.458617546671, 7, 6, 8.64711029733088, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315412410870000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24949181, 14.31003057, 246.884087120013, 7, 8, 10.8538398691813, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315412430880000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24959673, 14.31033509, 248.180905624572, 9, 8, 11.8312, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315412450890000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24965238, 14.31066123, 249.088334983872, 7, 8, 12.6028, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315412470900000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24978463, 14.3109267, 249.723078168309, 9, 8, 12.5685068628947, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315412490910000, TimeSpan.FromHours(1)), new GeoCoordinate(48.24994331, 14.3111727, 249.970473085232, 9, 8, 12.4484800654093, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315412510920000, TimeSpan.FromHours(1)), new GeoCoordinate(48.25010288, 14.3112952, 249.897850417847, 9, 6, 11.608293464152, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315412550940000, TimeSpan.FromHours(1)), new GeoCoordinate(48.2504877, 14.31153935, 251.089439133188, 7, 6, 10.8881333333333, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315412570950000, TimeSpan.FromHours(1)), new GeoCoordinate(48.25063711, 14.31161383, 251.629094482507, 7, 6, 9.91077352956136, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315412590960000, TimeSpan.FromHours(1)), new GeoCoordinate(48.25077697, 14.31164086, 251.939513239737, 9, 8, 9.08773349685669, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315412610970000, TimeSpan.FromHours(1)), new GeoCoordinate(48.25089215, 14.31165132, 251.956198505071, 12, 8, 7.79596221612368, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315412630980000, TimeSpan.FromHours(1)), new GeoCoordinate(48.25094566, 14.31162197, 252.531907983946, 7, 6, 5.73086814976673, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315412650990000, TimeSpan.FromHours(1)), new GeoCoordinate(48.25097386, 14.31163463, 252.696037530844, 7, 6, 3.77117962934291, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315412671000000, TimeSpan.FromHours(1)), new GeoCoordinate(48.2510034, 14.31162491, 253.075981838263, 9, 6, 2.64702266191533, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315412691010000, TimeSpan.FromHours(1)), new GeoCoordinate(48.25102581, 14.31159456, 252.590673123036, 9, 6, 1.97770819383125, 0)),
         new GeoPosition<GeoCoordinate>(new DateTimeOffset(634315412731030000, TimeSpan.FromHours(1)), new GeoCoordinate(48.25103794, 14.31161438, 252.78888905611, 9, 6, 1.61398873787711, 0)),
     };
    }
    #endregion

Answer 1

I do not think you have done anything wrong, the issue is (I believe) there is a great deal of data in a small vicinity. This means lots of sharp angles which with a quite high StrokeThickness this all melds into one blob.

A workaround which makes this slightly more eye pleasing is to change the StrokeThickness based on the zoom level (the more zoomed out the lower the StrokeThickness) something like the following :

private void mapControl_ViewChangeEnd(object sender, MapEventArgs e)
    {
        if (mapControl.ZoomLevel > 17)
            mapPolyline.StrokeThickness = 6.00;
        else
            mapPolyline.StrokeThickness = 2.00;
    }

I do believe this is something that needs to be looked into though.

Answer 2

Actually I rather think the problem lies not with Microsoft but with inappropriate use of the tools. It is normal professional practice to thin the data as one zooms out. For example, my company's web based fleet tracking product can show the doings of a vehicle.

For a journey of 48 hours, if you zoom out to a national level you will bring around ten thousand position samples into view. This is a ridiculous amount of data to send to the client, especially since the points will blur into each other ten to a pixel.

So we cluster them, with a proximity threshold that is a function of map scale. This gives us points about ten pixels apart in sensible numbers, with bonus noise elimination. Remember to cluster using proximity in time as well as in space, otherwise you might get inappropriate grouping in there-and-back routes.