I am finding that the touchscreen on my iPhone is not sensitive on a horizontal line at the level of the 4-5-6 keys on the numeric phone pad when the phone is activated. It often senses the "key" above or below these numbers. The area remains "insensitive" to touch on other applications as well at the same location on the screen, however it is harder to detect. The problem is most annoying when using the phone. Anyone else with the same experience? Any suggestions?