I can't delete this app that is installed on my iphone 4. I have no idea how it got there. I don't remember installing it. It is called "game center" and is on the same screen as the pre installed iphone apps. I press against it for a few seconds it starts wiggling but I never get an "x" in the top corner. The other apps I installed get an "x" but this one does not. It acts like one of the pre installed apps. Anyone have this problem?