I had the fun of not being able to get the 'Source Control' item back in the File menu of VS 2005. Very frustrating because I tried the basics like navigating through menus and option settings, uninstalling/installing Source Safe 2005 in hope that it would reappear in my menu - but nope....
After some 'snooping' around I found this posting to save my day:
http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=117391&SiteID=1
In short the posting says to register a Source Safe dll. Paste this one into the 'Run' dialog and push the button - Voila - it's back again ;-)
regsvr32 "C:\Program Files\Microsoft Visual SourceSafe\ssscc.dll"
Good luck!