One of the most common problems is one or more plugins/addons that either fail them self or fail if loaded in combination with other plugins/addons/vsipackages.
To work out if that is true in this case do the following:
- start a visual studio 2010 prompt
- type devenv /Safemode
- Check stabiity of VS2010
- Works? unload/remove plugins until you have a stable installation
- Doesn't work? Contact MS Support
The msdn documentation on devenv switches