Invalid file handle

In 10 yrs I have never seen this happen. When
attempting to transfer a file from a Win98
client to a WinNT 4.0 w sp5 via RAS the user
receives the following error…
Error copying file – cannot create or replace
*.* (where *.* is the file name)Invalid File
Handle.
This user has been doing this same operation for over 4 yrs with no problems. I have 5 other users doing the same thing with no problems. The only variable between this week
and last week (when everything worked) is
this users PC was upgraded to a compaq ipaq.
Any ideas?
Thanks