Dell Latitude e6400 new audio problem

So the e6400 has had many people frustrated with poor, or broken audio. However, I'm experiencing different problems than what I've seen reported, and none of the fixes I've found have worked.

The only audio that is messed up for me is audio from certain games. The two games I have on my computer that i have problems with are Portal and Stepmania. in both of these the audio is severely crackly and laggy. However, I have Jets 'n Guns where I experience no audio problems whatsoever. All audio outside of games works fine, music, movies, online content, it all works, and its the same through my laptop speakers and headphones.

My laptop is running XP SP3, 2.66 ghz dual core, 4 gigs of ram. I don't really know what I have for audio.

Please tell me if there's any more information you need to help, thank you.

EDIT: Just a quick update, system sounds like the beep when you change volume are also not playing correctly. I don't know what this means.