After fooling with it a little more (waiting on my replacement to come in), it is DEFINITELY a hardware issue. The capacitive sensitivity seems to have gotten super sensitive and ANY oil on the screen from skin contact sends it into "ghost" mode. If I clean it then use a thin napkin or something, it works okay. As soon as oil gets back on it though, it starts registering touches like crazy. It seems like the lower quarter is the most sensitive (sense it's probably had the most contacts thanks to the swipes to unlock it).