Help! It appears that when I fire weapons that require CS:S the sound screws up, resulting in a VERY different sound than what it normally should play. It ALSO makes some sound REALLY quiet, barely being able to be heard (IE: reloading, Portal 2 cores) I am in the process of reinstalling CS:S and seeing if that helps.
Try deleting the sound files in both CSS and gmod and then telling Steam to validate the game cache.
Steam will then confirm if you have all of the files and since you deleted them it will automatically replace them with the defaults from the GCF.
That seemed to fix everything, thanks.