I hope this can help somebody...
I talk about my experience with this error.
1) i have noise problems on audio with windows enterprise x64 and gigabyte ga-ex58-ud5 plus ATI HD 5.XXX with HDMI output.
I solved it with no installing the RAID drivers from mobo.
2)I have problems when i play a vid with AC3 or DTS the computer crash completly
I solve it going to Administrative tools -> computer managment -> and disabling the ATI's HDMI audio, installing the lastest drivers from realtek and everything works fine.
PD: I keep working with the problem of RAID drivers and sound problems.