A few weeks ago I purchased a Forerunner 405. It seemed to work fine except the elevation data were wildly inaccurate. For example, when I climbed a small peak in town with an 850-foot ascent, the watch said I had gained 1,500 feet. Garmin suggested I "reset" the watch, which I did, but it didn't help. I was then told the watch must be defective, so I traded it in for another. This watch is just as bad, if not worse. After several tests and bad data, I "reset" this one, too. Today I climbed the same mountain as before, and it says I gained 2,200 feet! Garmin says I must have got another bad watch, even though they've not seen this problem before. I'm thinking that is a coincidence. Has anyone else had similar problems with the elevation data?