Version: 1.2.1
CUPS.org User: twaugh.redhat

https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=192015

is an example of a case where the usb backend fails to print to a Konica Minolta USB printer, although the 1.1.23 usb backend works fine.

The difference seems to be in checking the printer status before sending the file.

The error_log file continually says "Printer off-line." with the 1.2.1 usb backend.