Sound problems

Im having sound problems with both the decrypted gp4 files. The sound comes out juddered when your on incar and outcar it screeches. I did have a c-media sound card which i thought was the problem so i got a soundblaster live 5.1 digital but it didnt cure the problem although it did seem to get a little better, though this is probably due to the quality of the sound card. Its strange because it doesnt happen with the original version. Ive also tried every combination in the sound setup options, can anybody help?

Specs - athalon xp2000 1.66ghz
Soundblaster live 5.1 digital
nvidia geforce 3 ti200
windows xp

Go to volume in the start menu and make sure the "wave" slider isn't pegged all the way. I had this problem with the 5.1. Also you can make your own preset using the S.blaster Live mixer, thereby you will have the same settings for every application you run.

Get 6.1 Dolby Eax - kicks ass on Gp4, THE CARS ARE EVERYWHERE