Myself for sometime now and a friend recently have both been having the same problem with our phones. Mine is a first gen droid, hers a droid 2. For some reason, and with out warning the touch screen will simply stop responding to touch. I've noticed this happens some times when I slide it open, though other times it simply stops responding when I'm in the middle of using it. Now I've used a magnet to unlock the phone and the rest of the keyboard and other buttons function properly. We've done the same with her phone with the same result. I have pulled the battery and left it off for a few minutes and had it snap right back to perfect functionality, and I've also pull the battery over and over multiple times and had the problem persist. Also, for some reason when my roommate who has his own ring tone calls maybe 30% of the time the phone will start working perfectly There does not appear to be any one action on either of our parts that seems to consistently cause or correct this problem.
Furthermore, more often than not when the phone is in this state of not feeling the touch screen attempting to use the phone as a phone or open contacts causes a .acore crash. If someone calls most of the time the ring tone will loop infinitely, or freeze up. Has anyone else had problems like this? I was thinking it might be hardware until my friend started having the same problem.
Both of us are using unrooted phones, and I factory reset my phone after the first big update because I felt it negatively affected my phone's performance, I don't know much info on her phone past it isn't rooted and has the same problem mine does.