If you're not using bukkit you need the ModLoaderMP for vanilla from here.
This is a theory but I think that the modloaderMp isn't for a 1.0.0 server, because when you go to the forum and download it, the client is 1.0.0 and the server is 1.0.1 and that might be causing an issue? does anyone have IC2 1.0.0 on their server? if so what all did you use? because I cant get the server to start when I add the modloadermp and minecraft forge 1.2.2 on the minecraft_server.jar, not even the 'mods' folder will be made.
it never gets that far and its driving me crazy, I just want buildcraft and IC2 on my 1.0.0 vanilla server.. this is my second day of trying to figure out the problem by myself