Thanks Sambones but Anzio has a keep alive setting that sends a null packet at user defined intervals which is set at 10 seconds. Firewalls are certainly a major source of problems though.
FYI, Anzio is the best Unix client on the market in my opinion. It has a print feature that passes of an ascii print job to windows for printing and automaically compresses the width. It also can create a PDF file instead of printing to paper. It also supports ssh. Sorry for the promo but I am really impressed with it after installing it on several hundred PC's.
Anyway, I have found info that indicates there are settings in the Windows/client registry that control tcp/ip conditions such as max resend of data before disconnect. I am going to play with those and see if I can delay the disconnect time a little to compensate for internet problems.
Again, thanks for the replies guys!