I'm having the SAME problem!!
card: HT Omega Claro+
OS: Windows 7 x64 Ultimate (build 7100)
Drivers: Vista 32/64 (only thing available, had to manually install this)
Of course I can get some type of sound out of my speakers (but it isn't 5.1). Not to mention the bigger problem of the system tray icon freezing up the entire computer to a grinding halt (requiring a hard boot) if I just click the darn thing. So, there the icon sits... useless... deadly... and just taunting me. No way to open up the control panel and no way to get rid of it (so it stops looking at me with that evil grin). I paid $200 for this card, I'm seriously going to cry if I can't use it... what a waste... Dang HT Omega, post Win7 drivers on your website like most vendors... please! You're killing us here... We pay you enough, its not like its a budget card or anything... SHOW US THE DRIVERS!!!!!!!!!!!