I have been refilling my Canon MP830 by German method for several years alternating between two sets of Canon cartridges and using a resetter. I have just had my second cyan cartridge apparantly go bad. It resets, but after istalling, printer tells me that there are more than one cyan cartridge installed. I installed a new cartridge and error message disappears and printer now prints okay. My question - is there a "drop dead" date embedded in the chip or did the chip just go bad? Any idea why only the cyan? Maybe the resetter (I replaced the battery with no help to with the error)?