If you're having problems with any of my mods, reinstall ModLoader. Then make sure you deleted META-INF from minecraft.jar. If that doesn't work, and you're sure you reinstalled modloader just now, it could be a blockID or itemID conflict. My mods will automatically create a file in (minecraft folder)\mods\DJoslin\, open that file and change the ID to an unused one. If you have trouble with any of these, google the problem first, then you can try asking the forums. Mods aren't officially supported so there are a variety of problems people can face, but someone else probably had the same problem and posted a solution.