Hey guys! There are two different Issues... Losing audio after sleep seems to be a problem with Multibeast 6.2.1 as the good people before me have already correctly concluded... Solution, like they said, is to eliminate all traces of 6.2.1 (or maybe just its audio kexts if youd like to keep the other upgrades) and then use the audio kexts from Multibeast 6.1.0... In my case I reformated and just went with MB 6.1.0 entirely. Nobodynose, I'm guessint your problem is that youre probably just running MB 6.1.0 and expecting it to overwrite MB 6.2.1... I think you have to manually delete the audio kexts that 6.2.1 installed FIRST or just do like I did and reformat and just use MB 6.1.0 from the beginning.
This is a different issue!!! The audio starts getting "garbled" and gives like a "lo-fi" "lo bit" sound with distortion and then eventually silences completely... It happened to me for the first time when I was listening to music really loud and I thought I had blown my speakers hahaha... But to my surprise the audio came back 100% clear after a restart or even a sleep and waking back up ( I didn't lose it after sleep because when this happened I was still using MB 6.1.0 hahaha so I didn't have ISSUE #1 yet)
I searched online and found people complaining about this problem on apple.com... (Basically non hackintoshers) It looks like its the system itself!!! I realized it happened to me shortly after upgrading to 10.9.2... So my solution was to go back to 10.9.1!!!
So in conclusion...
Issue #1 If you're losing audio after sleep... Downgrade (CORRECTLY! as in find out how to delete 6.2.1 completely) and then go back to Multibeast 6.1.0.
Issue #2 If your sound card/audio crashes very randomly WHILE you're using the computer... Sound gets garbled and distorted and then cuts out.... Downgrade from 10.9.2 to 10.9.1.
Hope this helps guys!