Small Time Hookup-Why is there a buzz?

[jahern]

I'm hoping that one of you professional show guys can tell me why, when I try to use the Line Out on my computer and hook it into my Receiver, I get a buzzing sound. I don't get this buzzing sound when using the headphones.

I'm using a 25 ft wire to string from the Computer to the Stereo. The fact that it is an extension chord doesn't seem to bother the Headphones.

Do I need a better set of cables?

Has anyone had this problem and resolved it in some way? (That would seem to be the most useful info.... But any suggestions are appreciated. I can buy stuff at FRY's here in California, and take it back within 30 days if I am not satisfied.

As I think about this problem, I believe that I have always had a buzzing no matter what the computer. Here is my current Sound
Card

Sonic Edge 5.1 PSC605

I imagine that if I were Hoster Man (doobie doobie doo..biddi biddi bum) I would need to know how to eliminate this annoyance.

Any help is appreciated