found this on Qusers.
This is a pesky little problem that has plagued a few out there, but not enough for it to be commonly known
Sometimes, the earpiece volume will get set to 0, and after the earpiece is unplugged, even though you're not in headset mode, even though Media Player volume is set to max, even though mute is off, there's still no volume because the earpiece volume is set to 0! Nifty, hunh?
Go into Media Player, start something playing. Press and hold-in the jog wheel for a second or two, and the Earpiece Volume will pop up. It will probably be 0. Just set it up to max, and hit done
Ridiculous, hunh?
