Speaker/sound Card Configuration?

I bought a new pc, Dell, with a Creative Soundblaster X-Fi Xtreme Audio sound card, and a Creative T6160 speaker set. The speakers should be a 5.1 surround system (and in facts i have 5 speakers + subwoofer) but it seems i can't make the subwoofer work at all. Had only 2 speakers working since yesterday, i played a little with the Creative control panel and it seems i made all 5 work together. The problem is that, from the Creative speaker test section (the one where you can make the voice play "this is the front right speaker", "this is the front left speaker" etc.) all works fine except the subwoofer. I looked at the back of my sound card and everything seems done right. Black jack is in the black hole, lime jack in the lime hole and orange jack in the orange hole. The Creative control panel recognizes them as 5.1. Still can't make the sub work. I even tried plugging the green/black jack into the orange hole and i managed to hear the "bzzzz" test sound which should come out from the sub, but nothing happens when i do the opposite (orange jack plugged in green or black hole).