I'm having trouble killing print jobs.

I'm printing a job (from CUPS to a local printer). For some reason, my printer messes up and starts dumping tons of random characters (since it is now in text mode, interpreting graphics data as text data). I want to cancel the job, so kill the que in CUPS.

BUT THE PRINTER KEEPS ON PRINTING.

I can even kill the CUPS daemon... it keeps on dumping data.
I can shut off the printer... it restarts dumping once it is turned back on.
I can check the printer que with "lpq". The que is empty, but it still prints.

Only a computer reboot clears the que.

It's like data is stuck somewhee between the CUPS daemon and the printer, but I can't get rid of it.

Anybody got any ideas?

Try physically disconnecting the printer from a power source and let it sit with no power for some time.