the resetting one is one that i've had a lot, and its not a glitch, its a hardware issue. my old 3ds had a lose battery and if you hit the back corner the battery would move, and unplug itself, and obviously turned off. when you started up again the time and on the 3ds would be 00:00, 01/01/11. in the end i had to send it to nintendo, where they gave me a new 3ds.
Yeah, I wasn't really sure if it amounted to a glitch or not.
It's a bit finnicky, isn't it? I've dropped my 3DS from ~six feet before and it didn't even give me the whole cart was removed thing, and all I did when the battery disconnected was set it down on my desk after I'd shut it off.