Printer held Hostage by Ink Cartridge

I’ve had a Canon Pixma MX700 multifunction printer since the beginning of the year. I’ve been pretty happy with it. It’s worked well for scanning, copying, faxing and printing. Until today. Today I needed to scan something, and was greeted with the following message when I turned it on:

U150 The following ink tank cannot be recognized.
The yellow cartridge was indicated. I though that it was an odd problem, but I didn’t care for the moment, because I didn’t want to print, just scan. But no button on the printer would bypass this error and let me scan.

I ended up calling Canon, and happily received a domestic phone rep. He had me try a couple things, but eventually decided that the yellow ink would need to be replaced. They would send me one free. I asked if there was any way to bypass the error so I could just scan, and he said there was not. If I wanted to use it today I would have to go out and buy a yellow ink cartridge. So after driving all the way across town and spending $16, I have my printer back…for now.

It seems like questionable design to cripple all the functions of the printer just because one color cartridge is faulty. A better failure mode would be to only prevent color printing. Black and white printing, and the other printer functions should still be usable. Hey Canon, how about updated firmware for this? Please?