Anytime I have a voicemail, I go to enter my voicemail pin and the screen goes black, then shows the number pad, goes black, shows the number pad, and on and on. This results in the recorded woman being like "Are you there?" or telling me that I've input an incorrect pin based on how it's detecting my selections. I can't stand checking my voicemail because this happens every time and have to try two if not three times to actually get my password in. Never had this issue with my SII, or on previous OS versions.
Good Wednesday Evening,
I have had that issue when entering my voice mail password and the screen goes black. It is not that there is anything wrong with the proximity sensor, this just happens when the sensor gets covered. This is normal on all smartphones. The sensor is programmed to do that to save battery power during a call, avoid the phone from heating up and causing any minor burns from the light of the screen. Not saying that any minor burns will happen. My best recommendation would be to hold the phone with your right hand and use your left index finger to enter the password. That way the sensor is not covered and your voicemail box will be accessible. Another suggestion would be to go into "settings" and raise the amount of time that you want the screen to stay on while entering your password. Anywhere between 15 and 30 seconds should be long enough otherwise the screen will time out sooner.