Comment 2 for bug 700990

Marking as duplicate of bug #564917. There and in the other duplicates the problem is caused by a USB-to-Parallel adapter but also Prolific Technology PL2305 in most cases. Please try the fix proposed there by booting from a live CD of Natty (and doing all updates after the boot). Does this solve the problem?

Also check whether the "usblp" Kernel module is loaded on your system, by running the command

lsmod | grep usblp

in a terminal window. Try blacklisting the module in

/etc/modprobe.d/blacklist.conf

unload the module via

rmmod usblp

then remove and recreate your print queue.

If the mdule is already blacklisted, try reactivating it by removing the blacklist entry, then removing and recreating your print queue.

Follow also the instructions under "USB printer" on https://wiki.ubuntu.com/DebuggingPrintingProblems.