"Cross-contamination is often the result of overfilling a color cartridge, and is not always reversible depending on severity," Elward explained via email. "When a cartridge is overfilled, the excess ink comes out through the nozzles of the printhead and runs into the chamber of the color next to it, resulting in cross-contamination."

The condition of the empty tank may also be a factor, says Elward. When a cartridge is stored in a plastic bag, for instance, the wrap comes in contact with the printhead. One color may seep into another's chamber. However, after several print cycles, Elward says (and as I experienced), the problem may resolve itself.

To give the G&G kits a fair shot, I emptied and refilled the cartridges a second time, let them sit a few hours before installing them, and resumed printing. Right away, the HP printer's LCD panel posted an 'Incompatible print cartridges' message. It stopped printing, too.

Elward says the error message is usually due to the printer's inability to read the chip on the cartridge. A variety of issues may be responsible, including a smudge on the cartridge's circuitry, or a feature in the printer manufacturer's software that might be designed to reject a refilled cartridge.