File corrupt when coping/saving to network share

Archived from groups: microsoft.public.win2000.file_system (More info?)

When logged into the domain, a network shared drive that has previously
worked, does not accept files being copied to it or saved to it (Excel file).
The error given is that the path is too long. If we do not log into the
domain, just the local machine, there is no problem. What could be causing
this.