My itouch screen is zoomed in just a little bit and won't zoom out. It can barely opperate since the buttons are off the screen. Is it set with an incorrect setting?

My itouch screen is zoomed in just a little bit. If I try to zoom out or in it will just pop back into place where about an 1/8 of an inch is off the screen. I can run my finger across the screen and it will slide in the opposite direction of the way I am trying to move it. I have tried restarting and restoring it and the same slightly zoomed in screen appears again. It is updated. There are times where it will fit properly for a short period of time, but it is random and I cannot see that I have done anything differently. I can't find any setting that would need to be adjusted and haven't really changed any setting. Any suggestions?