Mine has done this since day one...I dont even notice it anymore, but its still there...

 

Bump. Mine started doing this too. Any ideas?

 

sometimes mine beeps once at me when I'm dialing a call too. And sometimes beeps upon hangup like the op (and actually vibrates at the same time).

I have no idea the rhyme or reason to it, I've mostly just ignored but I am curious.

 

I just checked...I think it's the microphone button that is making the beep/vibration. I notice it changes 'color' when it happens. dunno what that does, exactly