SB X-Fi won't work with Gigabyte GA-M720-US3

Hello there. I've recently upgraded my motherboard to Gigabyte GA-M720-US3 (MSI k9n6sgm-v previously) and I'm experiencing a problem with my sound card. I'm using SB X-Fi Xtreme Gamer Fatality Pro Edition. On the MSI mb everything was working perfectly but it's not anymore. Everything in Windows seems to be ok I've also updated to the newest drivers. I can see my card in a device manager, I can choose it as a default playback device in a control panel but I can't get any sound from it. My on-board sound card (Realek HD) is working fine but X-Fi doesn't   . Yes I've turned off the on-board card in bios but it didn't help.

My set-up is as follow:
Gigabyte GA-M720-US3
AMD Phenom X2 965 Black Edition 3.4GHz
Kingston DDR2 2x2GB 800MHz & 2x1GB 800MHz
GeForce 8600GT
SB X-Fi Xtreme Gamer Fatality Pro Edition
Windows 7 Ultimate x64

Any advice what can be wrong?

Thanks, Bartek