I honestly have no idea why. Any mod that changes the terrain or changes how the world generates makes my game either crash on start or black screen. I know I'm instaling them right, because I have other mods installed (only Rei's Minimap, Optifine, and TooManyItems, though). I've googled everything I can think of, and no-one else has this issue. Any ideas?
It's working now though. Dunno why; I did another fresh install and it worked. Thanks for helping.