Pelle55,
Check to see how the user is opening the db. In access, open/file the "Exclusive" box may be checked. If this is checked, only one user can use the db at a time.
There is an option to set this as either shared or exclusive.
In access 97, in Tools|Options there is an "Advanced" tab where you can set the "defalut open mode" to either shared or exclusive. Check to make sure this is set to shared.
You would only open as exclusive as administrator if you were doing maintenance and wanted to lock out the users.
Jdemmer
God Bless