This is happening often. When I have an incoming call the call screen appears and phone rings. I go to answer by dragging the icon to the green answer icon and nothing happens. The phone continues to ring. Trying to drag to the red ignore call icon has the same result. Eventually the caller gets sent to voicemail, but the phone remains locked in this state and needs to be rebooted before it is operational again. I thought it was related to teh phone being in a lockscreen state, but it now appears to be random. I have contacted Google and they said they have not heard of this issue before. Essentially it is unusuable as a phone. Anyone seen this issue or have any idea what might be going on? I have the phone on Sprint if that makes any difference. Thanks.