Sound during a round

[FuRy1]

Using ulx playsound

Used this code and put it in gmod/lua

if SERVER then
resource.AddFile ("sound/nameofthesound.wav")
end

Obviously replacing the "/nameofthesound.wav" with the actual sound name.

And put the sounds wanting to use in gmod/sounds.

However this error pops up in the console;

"[LC ULib ERROR] Received invalid sound"

The sounds shows as though its playing but no sound is being heard.

I have fastdl set up on my server and clients are forced to download each sound.

Help?

[FuRy1]

Anyone?