We've been printing difax maps using g3topbm and pnmtops with good results until recently. Lately we are seeing many of the 4 panel maps being printed incorrectly, only two panels to a page and with those 2 panels being significantly larger than before. The perl script I use to do the printing is very simple and uses the following line to do the converting and printing:
Don't worry. It isn't your problem. It's the NWS.