Issues with safe mode and power button

My phone completely froze. So I popped the back off, removed the battery, waited and then reassembled it. When it restarted, it was in safe mode (never had it happen before). I swiped the notification bar down and clicked the option to exit safe mode. My phone restarted and I then chose how I wanted to restart it. I chose home & app drawer (what I normally run). My phone loaded up fine and I have access to everything once again. However, now the power button doesn't respond. I mean, I can still turn the phone on and off by double-tapping the screen, but can't take screenshots or use the power button in any way. Please help.