I am setting up a small network consiting of 10 WinXP Pro Laptops. I have
selected one of them to be the server and have shared the drive. Mapping
this drive to a workstation is not a problem, but if the "server" is
inactive for a period of time I can no longer find the computer when
attempting to map it to the next worstation. The one I originally mapped it
to still works just fine, but in order to map it to another "workstation" I
have to re-boot the server.

This has happend to me once before several years ago, but I don't remember
the fix.