Acer Aspire 6935G - Speaker problem

I bought Acer Aspire 6935G and is very satisfied with it, however one problem is bothering me:

Sometimes my speakers distort the sound coming from the computer, and it sounds AWFUL!
It can happen anytime, wheter I am listing to music or just browsing my files. (the click-sound gets distorted)

I've tried the following:
* Changed drivers
* 3 different OS (XP,Vista and W7)
* Reset to factory settings (Vista)

I've found some ways of fix the problem temporarly:
* Restart the machine
* Just ignore the bad sound, and countinue using it, and the distoreted sounds goes away after about 15 min
* Change sample rate, anyone would do

But the distortion just keeps coming back

If I connect headphones or a set of speakers when the distortion is present, I can't hear the AWFUL sound

I've currently uinstalled all drivers from Realtek, and currently use the standard audio driver Windows installed afterwards. Now the distortion has stopped, but sadly I can't use 5.1 sound. Therefore I need to get the real drivers work.

I¨m suspecting it may be the subwoofer thats causes the problem?^^

Suggestions?

Ive now been using the standard audio driver that windows installs. It work good, and the problem is non-consistent So I'm certain that its a driver problem

Can't help you with the tv-card charliepie, put I got my Cinedash controls working in Windows 7 Just download Launch Manager for Vista from Acer. Install WITH compability mode set to Vista