"Ink Cartridge Error" on 9880

I have had my color printer in Piezoflush while I was using my black and white printer for work for maybe three months. Today, I refilled my set of color cartridges, and loaded them back into the 9880. I am having that maddening game of the printer sill give me an “Ink Cartridge Error” on one of the slots. I re-seat that cartridge, and all is well, until a new slot shows the same error. I’ve tried unplugging the printer for 30 or more seconds, hoping it would forget the warning. I have also pressed the reset button (holding down the pause button) to no avail. The cartridge slot in error keeps changing, and it’s been going on for hours. Any suggestions?