sv_allowupload 0 does not work?

I am trying to stop file uploading into my server.People suggested that I use sv_allowupload 0 and sv_allowdownload 0.I have tried both cvars but only sv_allowdownload 0 worked.I was not able to download fiels off server but with sv_allowdownload 0 I still was able to upload files.

Any ideas?

You need to upload the engine.dll from your garrysmod/bin folder to your orangebox/bin folder on the server.