im not sure how to check if it is set for mono, but-
the soundcard comes with its own sound control program, a simple window showing the levels of all the channels. In that, it shows the audio going through both the left and the right channel (levels going up and down). If i pan everything to the right i hear nothing- if i pan everything to the left it will get louder.
So the audio is there, it's just not coming out of the right output.