Sound Problems on Youtube only CF-19

Well after the niece torture test the only problem reported was a Crackling sound when listening to Youtube videos. I took a listen and it sounds like when you have a blown speaker or loose wire. This only affects youtube videos. playing movies, music, etc. no problems at all. I thought it was a streaming issue,but the problem is there even connected to a hard wire 6mpps ethernet line. I have uninstalled and reinstalled sound drivers. i know flash is hard on netbooks,but my old cf-28 can play them fine. any ideas what to try?

CF-19 MK2 soundmax hd audio drivers

 

I mean, there is an other application like an virusscanner, running in the background, which is using ur RAM or harddrive with an higher priority. If I start an scan, my sound will also be chopped.

 

nope avast disabled. malawarebytes disabled. no open applications but Opera running Youtube.

 

Try Firefox? Internet Explorer 8? Safari?

 

Have u only one website opened? Maybe there is an site on a tab with a big flash-programmed ad, which will decrease ur performance. U can stop all unnecessary ads in Opera with an right click on the site and select "block content..." so the ad will not be loaded from the server
Also u can close Opera and open ur u-tube movie from the Opera-cache (cache4) and look, if u also get an scattered sound to be sure.

 

Well I found out Windows Defender (built in Win7) antivirus was running. I disabled it and applied a newer realtek driver. will hand it over to my niece for another weekend. if it is still there it is i think it might be a windows 7 problem. while googling around it seem windows 7 handles audio differently and that causes problems like I described. Thing is before I upgraded to Win7 there were no problems in XP. I never tried Vista as I just installed that for an hour to upgrade it to Win 7.