[color:"orange"] I'm not sure why a TV tuner card would be doing anything with PC generated sounds (assuming it can), but that could be part of the problem. [/color]
The weird thing is, my computer states that it's also a webcam.

[color:"orange"] I think the English word you are looking for is mute. [/color]
I feel really dumb now, I use that word almost every single day, and when I actually need it, I can't remember the word. <img src="/ubbthreads/images/graemlins/silly.gif" alt="" />

K, now back to the serieus stuff: the problem is fixed and it was all my fault!
I've got this program called Realtek HD Audio Manager, and it has a 'Mixer' tab, where you can choose which lines he has to play and which to record, I had enabled all on both, so it was recording all my music and stuff, I've muted them all except for the 'Microphone Volume', and now everything is fine, I can hear the other person talk, he can hear me, but he doesn't hear my music/sound.

Thanks all for your help, I'm happy the problem is solved, I can finally keep my music playing while talking with other people.

[Linked Image from miniprofile.xfire.com]