I have been shipping packages from the UPS website using Mozilla as my browser for the past year. I print shipping labels on a Zebra ZM400. Mozilla was the only browser that I could configure so that the label would be properly laid out on the label paper. When I tried to print a label today, no label printed. When I checked the Print Jobs, the status was "error". Then, Mozilla locked up and I had to restart the computer in order to use Mozilla again. I tried printing the label using Explorer and the label printed, however, I still had the same old layout issues.