Comment 5 for bug 318886

 "Inkjets have a limited buffer so they start printing as soon as they receive data." To clarify, it does not start printing this data once the job has been canceled. Only if you print another print job without unplugging the printer first, which as stated, is also the only way to stop the power light flashing and allow you to once again use the power button to power off the printer.

It would be helpful to design hplip such that this does not happen.