Windows 2000 and Word Perfect

Hi. I have a client with a small peer to peer network consisting of 5 Windows XP machines, and 1 Windows 2000 Pro machine. The Windows 2000 machine acts as a server for the others. It has a directory that is being shared and the other workstations map to it. Whenever the person at the Windows 2000 Pro machine opens an existing, or creates a new Word Perfect document and closes it…the other PC’s on the network cannot access it. Gives a message like the file is in use, or read only. Neither are true. If I log the user out of Windows 2000 – then everyone can access the files.

Please help.