Very good post about solving Sharepoint problems with TFS 2010
The Visual Studio WIT tools team has published a very nice post pointing the most common issues with Sharepoint and TFS 2010.
Check it out at http://blogs.msdn.com/teams_wit_tools/archive/2009/11/24/tfs-2010-beta2-troubleshooting-sharepoint-configuration-issues-tf249038.aspx
Enjoy!
Andres G Vettori, VMBC, CTO