This would be a digitizer issue. Is it only the "agree" button or are there other sections of the screen which do not respond to touch. Sometimes there is a vertical or horizontal dead zone and it can fall squarely on a critical patch of screen real estate. You can test this by selecting an icon until it wiggles and then move it around the screen. If it "drops", that means there's a dead zone and you will need to [guide|13724|replace] the digitizer.