Humid atmosphere wouldn't be a problem. Err... it wouldn't create any problems with the iPod, but I don't know if the sensor would pick up on something like that.
Nope. I called Apple, and I was told that they took it apart, etc, which I believed, but then I noticed that my iPod had barely been touched - it still had "Repeat one" set as the playback option, it even still had the same song, paused.
If a restore, or even turning off the darn thing gets rid of that memory, surely taking it apart would do so, too.