A week ago I had to disable the bookmark feature on this site because it was generating rampant SQL errors whenever anyone tried to use it. This was a result of updating the bookmark module to a more recent verion.
I will be going back to a previous (working) version. Unfortunately, when I re-install the bookmark module all previously assigned bookmarks will be gone. I apologize for this... I was hoping to preserve them, but in trying to fix the problem I wound up breaking it more.