perhaps someone can help me:
I've got a Canon S450 USB running with CUPS and sometimes, I have to cancel a job.
In the shell cancel [job-id] works for me, but cancel -a doesn't.
But since I want to do the printing-administration via browser, I use port 631, which works so far.
I can stop the printer, start and configure him, but I can't cancel the printing jobs, even my own,
even if I'm run the browser as root.