Netbook Audio Problems

I have an ASUS 1201n and so far I've greatly enjoyed using it as a main computer when I'm attending college away from home where my desktop is. However, when I'm listening to music with either my speakers or my earbuds, there are problems with crackling or lag in the background. So I overclocked my processor a bit and it became less frequent, which leads me to believe that it is a sound card problem.

I bought this:

http://www.amazon.com/Syba-SD-CM-UAUD-Adapter-C-Media-C...

in hopes that it would rectify the issue thinking it would be a dedicated external soundcard, so the problem persists which makes me think it's still using the netbooks sound card and amplifying the sound through USB (it's REALLY loud).

So what I'm wondering is, is this a common issue with netbooks and is there a easy solution? If not, would there be any adapters as dedicated sound cards I could buy? I'm wondering if these would do:

http://www.amazon.com/gp/product/B0044DEDC0/ref=s9_simh...

or this:

http://www.amazon.com/Creative-Soundblaster-Surround-Sy...

but seeing as how I've already thrown away money for a soundcard, I would like someone with first-hand experience to let me know if any of these works.

This is really irritating so any help would be appreciated.

Thanks!