Problem with pan balance, too light on left channel

Hi, I'm recording trax in Sonar X1 with an M-Audio Fast  Track Pro.  I have a dual core 1.6mhz with 8gig ram.  Playback on whatever I record is coming out strong on the right channel and weak on the left.  The pan is balanced in the center on the tracks.  When I am playing back, and swing the pan to increase on the weak channel side, it does not correct it.  Any ideas from the experts?  Thanks a lot.

FYI, this happens thru the headphones on direct playback.  It also happens when I take it down to a wav file and play it over the house stereo.  Also on mp3s.  No matter what I use to playback with.