Everytime I make a gaming movie with Adobe Premiere the sound gets scratchy when firing guns etc. It doesnt have this in the source video files nor in the previewing but only when I render it.

http://mechsweb.co.uk/~tunavid/Somet...ls%20Fishy.rar
a video with the problem

(same thing on google video, just cant hear it as well there)
http://video.google.com/videoplay?do...12605000097870

It only occurs when shooting the guns and there is a lot of sound.

Any ideas how to fix this?