i've seen you ask this question for some time. The definite answer for you is no. in fact i dont even notice any red light while making a call. of course my proximity sensor is working. If it does bother you, then send it to service center, if not then dont care, but it will drain your battery i can guarantee you that. I do know that the MIUI rom has a battery indication for the proximity sensor, so you can know if its really turning on by itself. Again i would suggest you also check your applications if there's any that's causing it.