So I downloaded forge 1.7.2 and mods that require forge, I placed the mod in the "mod" folder with forge, start up on forge profile, the mods don't show up. Do you need to have the right mod version? example: mod that is 1.6.4, will that work with 1.7.2 forge? Or do I have to wait until forge gets updated to 1.7.4 and use 1.7.4 mods?