Basically whenever i plug in headphones in 12.04 the sound plays through both speakers and headphones. Since release I have tried and failed to solve this issue many times. I know its not a problem with the headphones, and i know it's not a problem with the headphone jack, as using the same headphones on windows works as normal.

I reeeeeeally want to get this fixed ASAP, it is driving me insane, This is the first release this problem has happened.