Did you really use the /usr/lib/cups/backend/usb version which has given the "Memory fault"?
Please run Oneiric with all updates from my PPA. There run
sudo /usr/lib/cups/backend/usb
once with the printer connected and turned on and once with the USB->Parallel adapter disconnected from the computer.
In which situation do you get a "Memory fault"?
In this situation run
sudo strace /usr/lib/cups/backend/usb > log.txt 2>&1
Post all screen output and attach log.txt.
Did you really use the /usr/lib/ cups/backend/ usb version which has given the "Memory fault"?
Please run Oneiric with all updates from my PPA. There run
sudo /usr/lib/ cups/backend/ usb
once with the printer connected and turned on and once with the USB->Parallel adapter disconnected from the computer.
In which situation do you get a "Memory fault"?
In this situation run
sudo strace /usr/lib/ cups/backend/ usb > log.txt 2>&1
Post all screen output and attach log.txt.