Try and reset your prefs file.

It looks like it might be in there.

Rename your prefs file by going to C:User\Documents\maya\prefs rename the prefs foler to OLDprefers
for safe keeping.

Restart maya and a UI pop should ask if you want to use the old prefs or create new ones.

Say create new ones. This will clear up the corrupt prefs folder.

Copy all your old shelves and scripts prior to doing this so you can paste them back in to your new prefs folder.