As a first guess, see if you can persuade everyone to exit from the DB. Then, when you are sure they are all out (including you!), check for the existence of an .LDB file in the same directory as the shared database. If it is there when no one is in the database, you have a dangling lock file that is now desynchronized from reality.
Mechanically, what happens is, someone opens a record. They take out a lock. Now the LAN drops. Their query fails and their program exits (maybe), but because the LAN went away, their copy of Access cannot update the lock file. Now you have a lock file that contains old data in it.
If that doesn't work, repost in this thread. Perhaps someone else will have an idea for you.
