Audiophile 2496 recording stereo as mono?

My Audiophile 2496 works great in Sonar.  However, I've tried recording an audio stream off the Internet by playing in my browser, switching to Sonar and pressing 'record'.  I'm hearing great stereo and the meters in Sonar definitely confirm stereo.  But when I play back my Sonar track, it's either mono, or panned extremely narrow in the center, essentially mono.
 
My setup is that I come out of my Audiophile 2496 into a Spirit Folio mixer, stereo channel.  I go back into my PC through the aux outputs of my Spirit folio.  Like I say, it sounds great while playing, but when I record it and play back, it sounds mono.
 
Any ideas?  I've found the Audiophile 2496 control panel to be complicated - and so if there is a way to do this without going through the outboard mixer, that would be great of course.
 
Thanks in advance.
David Ewer