So I just recently purchased an HTC Evo 4G from some guy from craigslist, and I've been noticing some very frustrating problems. People told me that the previous owner might have rooted it then unrooted it. I need help. When I'm typing, it'll automatically start typing random things or crash. I'll have to turn it off every time, it's very irritating. It randomly calls people when I touched it once. Please help.