I set up a contraption with hopper minecarts and the curved rails did some strange things.

What I expected to happen was...:
The rails would function as they normally do.

What actually happened was...:
The rails did some very strange things. Some functioned normally, some didn't function at all, and some acted like full blocks, reflecting the Minecart in the other direction.

Steps to Reproduce:
1. Create a contraption with various powered rails and curved rails, all of which form a loop and face in different directions.
2. Power all the powered rails.
3. Place the minecart down and push it.