During my triathlon, I noticed that my Cateye wasn't reading any MPH. It was on, but wouldn't do a reading. I thought maybe it was because I had racked my bike the night before and it was water damage or something.

I took my bike to the LBS the next day and asked if he knew anything about Cateyes. His response was, "I know they're confusing." Great. I told him my issue and he said he thought he could fix that. So he tightened up the sensors and it started reading a speed. Great! I'm on my merry way when a few minutes later, I realize that it is reading waaaay too fast of a speed (like 10 mph above what I think I'm riding).

DH recalibrated the thing last night, and now it's back to not reading any mph at all.

Any ideas?