I'm having troubles with minecarts with Forge #204. They won't go uphill even if all the tracks are powered rails(and if it's only one block), and when the come back down to were flat ground is they sink into the block.
I thought it could have been Minecraft at first, then I tested it with no mods and the carts worked fine, but when I tested it with only Forge installed in the .jar the minecarts went back to not going uphill and falling into the ground...
It's making it quite impossible to do anything that involves having carts go up or down.