Bike Forums - Cateye Commuter Issues

Does anyone use the "Cateye Commuter" computer? Last night, my Blackburn Atom 4 fell off of my 1971 and I had to have it put down (its little brain was still trying to process information even though the display was shot). When I installed the new one I was able to reset the mileage back to that of the previous computer easily. Then, I tried to do the same with my Cateye Commuter on my 1972, following the directions to the letter. Each time I selected the "MENU" button to supposedly save the setting, it defaulted to zero miles. Yes, I reformatted the whole thing starting with a blank memory (the computer, not mine:D). Any thoughts??