Sometimes my iPhone 3gs zooms in slightly. Is it a bug or something?

It is as if it adjusts to the increased screen size of the iPhone 5. I know that it is not the regular zoom function of the iPhone, because I know that this looks a lot different and zooms a lot more. I could live with it, if it wasn't for the fact that it disables the function of unlocking the phone, since it zooms in slightly in the upper right hand corner, and stays there. It also disables the function of turning off my alarm clock in the morning.

I usually solve the problem restarting the phone, but does anyone else have any experience with this bug?

Thats odd.go get it checked out.