It does sound like a Novell compatibility problem. Are you using the latest client (v3.1)? In any event, there's probably some things that can be tweaked..

ex: Dos machine running Fox 2.0 app attempted an exclusive use, failed, then moved to the next table in the directory, attempting to get a license file. It worked fairly well. The same code on a win95 machine with Client32 would take 4-5 times longer to get the license file. Eventually, i realized it was because the dos machine attempted the file lock once, while the 'improved' client32 had the win95 machine attempting 5 times with an interval in between tries.

You'll probably have to play with the buffer/caching on the local machine until you figure out the 'right' configuration - then apply that configuration to all the client machines that use the application. When you're all done with that, you'll still be running an old app on new machines. Consider a rewrite of the app in a newer version of Foxpro (even if you must outsource it)