this isn't a bug - it was working fine until I had to restore the database for our site. After the restore all the fields that were previously set to auto increment were blank and now if I try to search for a user in the backend it just gives a blank list every time. Also users logged in to the site don't have their member group shown - its just their name instead of 'registered member' etc.

If anyone knows what the solution might be I'd be very grateful