when you restarted did it do a chkdsk?
If not force it to do one, your firefox profile will be in a slightly corrupt state (lost chain), chkdsk should recover it.
You can also check in the actual profiles directory, search teh text of files for something you know would be in there (Accyweb for example)
IIRC FF uses a bookmarks.htm file to store them. You do have a backup don't you
Actually thinking about it this could also be teh cause of your graphics driver corruption!
make sure you do a PROPER check for bad sectors etc!