save document message

While using Excel 2000 on a Novell 5.x network with Windows 2000 clients and MS Office 2000 I receive the following message: Document saved successfully. Cannot reopen the saved document due to low memory. Please close the document. The save works fine and I can continue to work on the file. I have tried this on several xls files with the same results. I do not see an memory problems. Office has all the latest patches. Could there be a problem with a MS Office patch?