It might be a stupid suggestion, but if you have it hooked up to a stereo with multiple inputs, perhaps you have the stereo set on a different input by mistake?

Just throwing it out there because I've done this myself.

No stereo hook up /

So i installed a 2nd soundcard, soundblaster which i believe it sees corectly asa ens1371. So now i think i'm making a big mistake somewhere because even after runing alsaconf and making this card active i cant get sound out.....how do i make sure i dont have sound muted in mythtv? M?