the refillable green cartridge engaged fine after the initial fill with Neutral K7 inks in the 7900. after removing them to reset the chip, the green cartridge will not engage and click into the slot. some of the plastic pieces on the side of the cartridges have gotten stuck and dislodged when removing the cartridges. the green still has the side piece, but will not click into place. I'm able to push it into the slot without resistance, but it does not click in. Please advise.