Access 2000 Database Allows Only One User at a Time After Being Mo

I just got a call from my previous employment location. An Access database
that I wrote which has been operational for over four years was moved to a
new server. The new SA put all the users in a group and gave the group full
permissions to the folder and all the files in it (both NTFS and file-sharing
permissions). Apparently after a few days, only one user can open the
database at a time. The first user who gets to the file can open it.
Subsequent users don't get an error message or anything -- the hourglass just
sits there until they hit Ctrl-Alt-Del to cancel the operation. The SA
wanted to know what I did to their database... I haven't even thought about
it in the seven months I've been across post.

That said, any ideas about what they could try to resolve their problem? I
told the SA that it sounded like the database was being opened in exclusive
mode, but they should be getting an error message if that was happening.