Just wanted to post that I think my "issue" with my Garmin 500 has been resolved. Went for a 33-mile ride this morning, and it was working perfectly. I did upload a software update to the device last night, but I'm beginning to think that my issues I had were related to what somebody else on here pointed out in their post above...that the device was never fully "started" so it kept going into auto power-off mode. I think what might have happened is...a few blocks from house at the start of the ride, I noticed that I wasn't getting a speed reading. I'm guessing the computer, having not detected a speed signal, automatically powered-off. After I adjusted my sensor to finally pick up a speed signal, I must have never "started" the timer back up again, so it continuously went into power-off mode for the remainder of the ride. At any rate...problem has been solved and it's working fine now. Yay!

Linda