Well, I tried to install Official Comments plugin and messed up the code (and never made it work) so now when I deactivate the plugin, the whole comments system stops working Can someone give me a hand? It's the blog in my signature. Thanks!
The first thing to do is replace the comments.php file with version you had before you applied the plugin (if you made a backup) or failing that with the original from the wp base install. Keep a copy of the current one in either case.