You mean mute people in the way they can't post replies etc? It's part of the warning management package "Visual Warning / Post Moderation". Dunno about links, but I think you can find it in the built-in package-manager. If not I'll see if I can send you the files.
i found it at smf mods , btw as far as i know it would only work on the default skin , i remade it so it works on all themes , if tkc want to change skins and retain the user mod i can do that for you.
eg
also checked into the uplaod attachments problem you have ..
the problems are in Display.template.php and ManageAttachments.template.php
in the default theme folder.
to fix: replace both of those files with the origionals and the problem should be gone.
info : smf checks themes for ?commands, if something is missing it runs back to the default folder and loads default if something was wrong in another theme or missing command in default.
good luck hope you get it fixed
Medic