SOLVED:
I was using the current transmitter I had purchased as a replacement for a "fob type" I had broken.
When you purchase a new transmitter it is equipped to work with all the Genie products, not just the one you own. Numerous attempts with the new transmitter failed to behave as indicated in the owners manual.
So, I thought, (like another poster said) its off the shelf tech, its probably NOT the MKC, its probably not the garage door motor as I have programmed other tranmitters. What's left? The transmitter itself.
SO I dug out the old fob transmitter that came with the opener and tried again.
About 30 seconds later, I'm in! Worked a treat!
So, having problems? Try using the OEM transmitter.