Wrd & Excl have intermit. problems savng

I have a workstation on a mixed Windows 2000 Active Directory and Novell 4 and 5 network. Periodically when attempting to save a Word or Excel document to a network share or a floppy drive, you get a end task now dialog, as if you had pulled up taskmanager and ended the task. This machine appears to be virus free. I have downloaded and installed all existing service packs and updates.