First check the cable, make sure it's plugged all the way in and is a 3-conductor cable on both ends (i know, you're probably not an idiot, but I gotta ask!).
Then, can you make a test signal that is just left and then just right channel and see if you're getting both channels summed, or just one channel duplicated? That might be instructive.
the thing says it's stereo... is there a software / system control panel for it?
What recording software are you using? (oh, adobe audition - I know nothing about that one - check the control panels?)