Strange audio stuttering on clean Mountain Lion install...

Hi,
I had a Hackintosh partition on my pc since a while ago and I have just updated it to Mountain Lion (from SL 1.6.8 but had to do a clean install since overwriting didn't quite work).
It all went amazing, booted from a USB with UniBeast on it (had to set a bootflag "PCIRootUID" tho), erased the SL partition to MacOS Journaled, installed, booted the new OS from the USB with the same bootflag upon install, no kernel panics!
Then, I downloaded the new MultiBeast and the appropriate DSTD for my board (MSI P55-GD55) from tonymac's database and ran MB with:
UserDSTD
Lnx2Mac internet
2>GB Fermi Nvidia patch
and, since audio didn't work at first, I found out my MoBo needed the ALC889 codec and so I selected it (the nonDSDT ver since the other one didn't work).
Everything again went amazing, Snow Leopard never managed to get close to this perfection. Everything worked (even sleep!)... or so I thought! As I said audio worked great immediately after the installation BUT as soon as I restarted the PC it started stuttering/crackling and prolonging the audio on EVERY sound source (youtube,iTunes you name it...), but, and this I found out by accident, when I was moving the mouse cursor the sound was just fine!
I've been scratching my head with this for days, first was restarting the PC a lot, then reinstalling the whole OS, trying different audio codecs from MultiBeast, repaired disk permissions but nothing seems to help
The only thing I have been leaving for the end was DSDT since I really don't know anything about modifying it (the one I use is the unedited vanilla version for my board). Should I turn to that? Or is there an easier solution?

Its my first time posting on these forums, so sorry if I made any mistakes
Thanks in advance!

P.S. another thing which was bugging me was whenever I try to boot with my 2TB external HD plugged in Chimera won't load (black screen with "\" symbol). I recently partitioned 400GB for TimeMachine on that disk and before that Chimera was starting just fine... :/ what could be the problem?

EDIT: Just updated to 1.8.2 and the problem still persists

EDIT2: Strangely enough I somehow found out that when my Diablo 3 launcher is downloading an update the sound problem somehow vanishes! of course when I quit D3 it comes back again -.-

EDIT3: Using EasyDSDT (precisely NullCPUPowerManagement.kext) seems to have fixed the issue, but I would still like to go the other way, cause now my CPU always runs at full freq. AND of course sleep doesn't work no more! (1.8.2. hangs on easydsdt too...). BTW Audio still crackles at some sounds, I am not a sound perfectionist but the audio quality is not even close to good

I just posted a similar issue for my asus p7p55d-e pro. I hope someone has seen this before
http://www.tonymacx86.com/audio/77954-p7p55d-e-pro-odd-audio-problem-via-chipset.html

this was solved in my post above

As you can see it was actually me who "solved" your post, but again I still need help because using NullCPUPowerManagement.kext disables sleep which was working fine until now and the audio is still not without errors. I am, again, no sound junkie but I would like to be able to listen to some music without being annoyed with crackling :/ Anyone?

Duhh Anyways, have you tried looking at the Audio MIDI Setup and lowering the output frequency of your audio to something like 44.1khz? I don't know why this configuration is under a 'MIDI' setting, but this may help you.

Yep, tried it but my default is already set to 44.1.. Was looking around a lot and it seems that there is no way to have sleep working while using the kext nullcpupowermanagement but it is the only thing that fixes my audio problems ><
Btw, how is your prob going? fixed it? does your sleep work?

When you gave that warning, I actually disabled sleep and haven't tried it... I spend most of my time on Windows, switch to Mac for app work so it's not a huge deal, but I can give it a shot. The sound is perfect after the fix, thanks

What exactly is the audio problem you're still having?

Occasional crackling on some songs etc. nothing much tho...

Sleep doesn't work

yup, the kext doesn't allow it to, tho as mac starts up/shuts down amazingly fast I practically don't need it