USPS Shipping Assitant printing problem

[evolver]

Expecting a large number of outgoing shipments, I decided to give a try to USPS Shipping Assistant. If we put aside slow and awkward-looking interface, the application does what it is supposed to do and does it well with one important caveat. I could not make it print shipping labels directly to my printer. I can print to a PDF by sending output to a PDF-writer driver. Having done that, I can print the resulting PDF-file normally. But it silently fails to print on my printer directly from the application.

I tried removing and re-installing printer drivers. I even hooked up the printer locally. Nothing seems to help.

Did anyone experience this problem with USPS Shipping Assistant or any other application under Windows XP?

Any hints will be appreciated!