There is a sound mod that nearly all the wav files have a static crackle at the end of each file....i had to edit the last 0.25 seconds off over 100+ files in a MP3 edit program to get rid of them, i can't remember the name but that's one of the mods that i use sounds from. Is that the problem with the sounds you've installed?
To replace your old wav files just install a second copy of the game to a temporary directory and copy and paste the wav folder over, it'll be a damn site quicker than having someone email you that many wav files.