I've noticed this a couple times now and am starting to get concerned. I have the backlight set to shut off after 1 minute of inactive use.

I also have the power settings to shut the device off after 1 minute of use. Every so often the device starts doing something interesting.

After 1 minute the backlight and screen both shut off (or appear to I should say.) If I look closely I can still see all the icons visible. It's not actually shutting off. I can touch the screen and it starts right up again. Any idea how I can rememedy this issue? I always do the soft reset and it seems to fix the issue but it drives me nuts.