Wow, just read this. Mine has done this a couple of times, but it was mostly around the time that I was frequently changing the device configuration. Have you been making a lot of changes?
Otherwise, I'm not really sure why it would do it. Unless it has a "safety" mechanism that resets it when its RAM gets full or something, I have no clue.
I work with computers for a living, but I've only recently getting into smartphones. My first thought would be an error on the device caused the reset, though.
