Thanks Walker, but that was not the issue here. The issue is, and remains, the fact that MK and LK are not recognized when I insert the new chipped cart. Wells sent me a new MK cart, so now I have two new MK chips, one new MK cart, and the only one that works is the old cart with the old - battery operated - chip on it. This is where I need to get help.
You thought it may be the LK cart/chip combination that may be the origin of this debacle? Is there something I can try to verify your suspicion? Or would replacing the LK chip with a new one solve the problem, in which case I would have to ask Wells for a spare. But again, let me know what your thoughts are.