Canon Pixma MP480 "Low Ink" error

Hello,

I have a Canon Pixma MP480 which is reporting "Low Ink" to my computers (Mac OS X v10.6.6) when it reports full ink on the little printer status screen. These are brand new Canon print carts not refills or off-brands. I have tried three different computers (a MacBook, a MacBook Pro & a Mac Deskside), power cycled, tried two different brand new color carts. Same on all computers.

Has anyone else run into this problem and worked up a fix?

Prior to this report of "Low Ink" it has worked extremely well and made high-quality color prints.

TIA,
Bob