guild wars music laggy

I had recently bought an hp vista laptop, however I noticed music with guild wars is laggy. And yet, it is only guild wars.

I tried all the different sound quality configurations in options, but still no cigar. Any ideas what could be wrong and how to fix this?
It only happens with guild wars, where the music gets abnormally lower and laggy, and such.
I tried reinstalling it, however, the problem persists. And it only happens at some parts of certain songs.

The most common song with this problem is kryta's main theme, if you know what I'm referring to.

edit: fixed a typo

Check to see if all the drivers are right for your soundcard.

Back

And all the drivers should be correct.
It is only Kryta music in places like ToA and such that experience this problem.