Well, I certainly suspect the customers network connection to the printer which is over a WAN across half of Europe, but proving that is the problem is another matter.
I can replicate a "Connection reset by peer" error on own printer by pulling the network cable out of the printer. And again I thereafter get the issue of "Connection refused" for what seems a variable amount of time. But at least I am now reassured that the "Connection Refused" is not due to something my script has not cleaned up. Thanks -- http://mail.python.org/mailman/listinfo/python-list