Excel 97 working with Win 2000

I am having an ongoing problem with Windows 2000 machines. In Excel 97 the user receives an error when they try to save a file. ‘Your changes could not be saved to ????.xls but were saved to 4CCA4100. Close the existing document, then open the temporary document and save it under a new name.’

Microsoft has a known problem with this message when saving to a networked drive. In my case we are storing this file on the local drive. The user is logging into our NT 4.0 server.

Any ideas??