Hey. I have 4 speakers on my computer but only 2 are working at the moment

2 days ago my dad got a new sound card so i got the spare one inserted. After installing the creative sound drivers that came with the card i did a test. Front left Front right Rear right and Rear left speakers were all working. I decided to play some music and noticed that only my 2 front speakers were working :o
So i went to test speakers again and they were all working. They're all plugged in right and connected to my computer correctly. The same happens in game.
Any solutions?
PS. it's a 24 bit card
PPS. I'm using winamp