I have the 16gb model, originally purchased on launch day but replaced about a month ago (broken mic on top). For the last week or so, I have had to turn my phone off at the end of a call because the screen is unresponsive. I can't use any numeric menus (I have to hope the company sends rotary callers straight to assistance or I'm screwed) and I can't mess with any menus. When I press an icon, it turns blue but doesn't activate. When I turn the phone off, I have to hold my finger on the slider after I bring it over to get it to actuate. I've cleaned the screen and looked into as much as I can but I can't find any fix to this issue. Have any of you had the same problem or am I alone in this? How can I fix it? Edit: I forgot to mention that it's on the 4.2.1 OS. If there's any additional information needed, please ask.