My server is OS 9.2.2, AppleShare IP 6.3; about 25 Mac clients running
either 10.3.x or 9.2.x.  One of my users is running Word 98 in
'Classic.'  Unfortunately, we still use several 'Classic' apps.  She
can save Word docs to her desktop, but when she tries saving to the
network, quite often she gets this message from Word 'The Disk Is Full
or Too Many Files Are Open.'  This will happen even when she has only
one document open in Word.  Adjusting the memory allocated to the
application doesn't help.  Funny thing is, I can then take the desktop
saved document and copy it to the network - at the exact location I
attempted through Word's 'Save' dialog box.  I turned off "Allow Fast
Saves" based up the results of a Google search.  It didn't remedy the
problem.

There is a long discussion of this particular bug in Word (for both
Windows and MacOS) here:

http://blogs.msdn.com/rick_schaut/archive/2004/05/19/135315.aspx

There's been a fixed released for Word 98 in a service release
(apparently), so I'd suggest trying to install the latest one
Microsoft offers