Visual Studio 2008 Shell (integrated mode) is used by Team Explorer (client to Team Foundation Server) as well as SQL management tools.
If you install Team Explorer AFTER you install Visual Studio 2008 SP1 then Team Explorer will regress some of the VS Shell files to the RTM patch level even though Visual Studio itself is at SP1.
Rerunning the Visual Studio 2008 Service Pack installer should patch up the files that the Team Explorer install regressed, no need to uninstall the Shell.
See this detailed description.
To paraphrase, the install order is important and should be as follows:
- Visual Studio 2008
- Team Explorer
- Visual Studio 2008 Service Pack 1
- SQL Server