We have seen some pretty goofy problems with Word over the years.
You know it is a MS Word problem when only one station does it. If every station on the system suddenly starts having a problem then you can suspect the network.
If Word is locking up or having memory errors when you try to create letters on cases you should first try un-installing Word (or Office) and re-installing. If that doesn’t do it you have to completely reformat the drive then re-install EVERYTHING, including Windows, Office (Word) and QuickLaw.
We know it is ugly, but it may be your only solution to the problem.