Saving/Printing docs over the network

I have two NT 4 workstations that periodically experience problems with saving or printing Word documents. It’s either the latest changes are not saved or when trying to print, only part of the document comes out on the page, the rest being blank.A second attempt usually work fine though.

These two machines are in close proximity to each other, and the first thing I tried was to replace the cables. But these intermmittent problems are still happening.

What else can I test for to help isolate the problem? I guess it could be NIC related, but I am not sure how to accurately test it. Any suggestions will be much appreciated. Thanks!