Cracking sound at exact part of videos

Hi every one!

i have an annoying crack/pop sound at specific part of some videos/movies.its a shot crack/pop sound but annoys the hell out of me especially while happens often.

at flash video like this too http://www.youtube.com/watch?v=aS1BNbFkSbw

at 0:10-0:11

it happens while i adjust the volume in youtubes volume bar too
at this exact same video.(mini crackings while moving the slider up down , then stops after a bit)

oh and sometimes i hear this while im saving in couple of games.

what have i tried?
:
checked the the plug
uninstalling / reinstalling audio driver i let windows use the default one too.
codec packs uninstall,reinstall,newer ones etc
disabling sound enhancements in control panel
(none helped)

i havent noticed this problem while i was using XP pro

i have Vista (64) now

and its a on mobo(Biostar TA770 A2+ SE) realtek sound


this problem is driving me nuts , id appreciate any helps/tips .

thanks
.

did that,no luck