1) Make sure that nothing is muted in the Mixer (Line In is muted by default
   in order to prevent speaker blowout). 

2) Make sure there is nothing plugged into the card except the speakers.
   The inputs are cut-off jacks, so an external connection will override 
   any internal connection. 

   Note: Being that this is a higher end card, the cirquitry was 
     intentionally designed this way to ensure quiet recording through
     the Line In.