Even on computers, they sometimes need to be sent out. Things like replacing a HD or memory, which just involve taking a cover off the bottom, are simple, but very little hardware work is done in the store. They could do a software restore, but that's it.
WOW, I have the same problem with my IPod. If you've found a solution please tell me. Because I'm practically stuck on one application and I cant go back unless I restart the whole iPod Touch. So please if you've found a solution respond to this message immediately.