Remove the parentheses from the ScaleHeight
method:
Sub Insert_Traverse_2a()
Dim oPic As Shape
Set oPic = ActiveWindow.View.Slide.Shapes.AddPicture("c:\users\david_zemens\desktop\logo.jpg", False, True, 0, 0, -1, -1)
oPic.ScaleHeight 100, msoTrue, msoScaleFromTopLeft
End Sub
Also, make sure you're reviewing the correct version of the documentation. What you linked to is for VB.net, not VBA for PowerPoint:
http://msdn.microsoft.com/en-us/library/office/ff743874(v=office.14).aspx