Yes, its a known issue!  I stumbled across this problem after installing LINQ a while back.  Luckily there is a fix for the problem.  Just follow the steps below in the order provided and Visual Studio will be back up and running as expected.

  1. Close Down Visual Studio
  2. Start Regedit
  3. Open the following key: HKEY_LOCAL_MACHINE\Software\Microsoft\VisualStudio\8.0\Packages\{A066E284–DCAB-11D2–B551–00C04F68D4DB}\SatelliteDLL
  4. Edit the “Path” value and change it from:
    “C:\Program Files\Microsoft Visual Studio 8\VC#\VCSPackages\1033\”
    to
    “C:\Program Files\Microsoft Visual Studio 8\VC#\VCSPackages\”
  5. Go to C:\Program Files\Microsoft Visual Studio 8\Common7\IDE and run the following commands in order:
  1. devenv /setup
  2. devenv /resetuserdata
  3. devenv /resetsettings CSharp

After this, restart Visual Studio.  Your intellisense and smart tags will now be working as expected.

Have fun!