first log in as another user with admin rights and check if the problem persists. if not, then its your profile that's to blame. in which case, do the following:
try a fresh profile.
first, create a folder to keep a backup of your old profile in.
right click my computer, select user profiles, highlight your profile and click copy to.
browse to the local of your folder you created. under "permitted to use" select everyone.
once the profile is copied, log off and log on as another user with admin rights. go back into user profiles, select the username you usually use (i.e. the one you think has the profile problem) and then select delete.
once deleted, log back off and log back on as your usual account. the profile will be regenerated, including a new ntuser.dat file which is imported into the hkey_user part of the registry when you log on. this fresh profile will resemble the default windows settings that you got when you first installed windows.
go into the folder containg your older and restore desktop items, favourates, etc.
the suggestions that i made were based on looking through knowledge base on microsoft's web site. there wasn't a lot of information, which is surprising since my search parameters were fairly wide. i could not find any more information than i posted but i may have overlooked something.