Mine started beeping also, mine had nothing to do with inactivity. It was the same beep as if you were turning the abcd dial, and when I started playing with it I noticed that some letters on the dial did not beep. I also noticed it was changing channels when it did it. Started picking up different riding group.
We use the letter A, on a specific channel with a specific sub channel, and the radio being locked, when it started beeping I would hear other people, I also would key the mike and they would hear me, while sitting beside others in my group whom could no longer hear me. We looked and the mike was still on A but the channel was not correct.
This was only on the new 2.0 radio, I was the only one in my group using the new one. I took it back to my local dealer and showed them what it was doing, even left it beeping on the desk so they could experience the joy of the new radio's also.
If nothing else at least it's expensive.