It seems that cupsys version 1.2.1 has some major problems - i've read alot in other forums about this. (just ask google) For our knoppix there is the possibility to apt-get cups version 1.1.23-10sarge1 and this one is working. Unformtunately you have to remove the cupsys-driver-gimpprint and cupsys-driver-gutenprint because they depend on 1.2.1 of cups. Maybe someone knows a deb source (for the sources-list of apt) to get an older version of those? They provide better drivers for my CANON and other printers.