I have a 13" 2010 MBP. When my headphones are plugged into the jack, and no sound is being outputted, the headphone jack seems to "turn off". This is real anoying because if I want to do something that outputs a sound, like emptying the trash, there is a 3 second delay from when the trash is emptied to when the sound is played. I just want to know if anyone else has experienced this? is it normal?