Suddenly, a section of my iphone screen is unresponsive. The area of the screen right above the 'dock' area, where the last row of icons resides on the home page is impervious to touch. The rest of the screen works fine, but just this one strip of screen does not detect touch. There are no visual indications that anything is wrong. This has been extremely frustrating in trying to type both messages/emails and phone numbers. I've tried restoring, resetting, installed 3.0, etc, nothing seems to help. Any advice? Can't find any information on other fixes.