network trouble

I use navision 3.56 running on a 2000 pro with 2 cliens. Then we had a problem with one of the client who left the data base on her lokal harddrive (a win98 machine) so I had to move her copy of the database to the win2000 pro machine, here navision runs as a service and has been restartet. We can now log on to the database from one client but when we try to get both client to log on navision says that we can not access the database as it is already in use. Can anybody help with this problem