Yesterday I actually discovered a problem. Let it be known that the problem is probably NOT with the audio selector, but rather my sound card hardware. I have a Sound Blaster Audigy SE PCI with the separate Sound Blaster Digital I/O Module.
The I/O module is used for S/PDIF input to my sound card from my Sirius tuner. I have the I/O module plugged into the 2nd port of the audio selector. When I try to run Sirius, there is no audio. When I plug in the I/O module directly to the input port on my soundcard, there is audio. This leads me to believe that there is hardware-based control on the soundcard that lets the line-in be, S/PDIF or Line-In, but not both.... I probably need to get a different sound card with more input options... Anyone else have any experience with this?