no but seriously...sounds like you have a cold solder joint in that guy. Listen to it again and wiggle the cable...does it go in and out in that channel? Next take the lineout (not the headphone out) and run it into an amp of somesort...if both levels are the same than it is most defiently the headphone jack needs to be re soldered. I would also try your headphones on another source (you gotta IPOD right) to make sure its not the headphones!
I am not that guy, I actually lost the bid that time. I suspect the capacitor is not working properly, but when I open the cover, there are 2 pairs of capacitors, I have no idea which one to change, one pair is round shape, 330uF, the other is square, 100uF.