try re-installing
I had similar problem but i had high pitch noise... i tried to update my SB Audigy Gamer without results. I re-installed the sound card, put it in another slot and then i was able to update on creative website and "vola" it was gonne. Just make sure that upon unistalling u dont delete some important file, i did, it took me 4 hours to sort it out....
In addition u can unistall ur drivers and re-install it from creative disk, then try to update.....
Hope it helps...