Minecarts with animals will sometimes reverse direction unexpectedly when traveling on rails and will not always stop on unpowered Powered Rail and instead reverse direction. Those times when they do stop, they will start moving after a few seconds without pushing them and without powering the Powered Rail. Often the animals will become invisible. So far I have tried this with pigs and donkeys....the donkeys seem to be worse. Did not have this problem in 1.8.x.

What I expected to happen was:
1. Load donkey into minecart
2. Push minecart to get it moving
3. Donkey/minecart continues along the track until stopped by unpowered Powered Rail

What actually happened was:
1. Load donkey into minecart
2. Push minecart to get it moving
3. Donkey/minecart suddenly reverses direction after travelling ~10 chunks OR donkey/minecart contacts unpowered Powered Rail and reverses direction
4. Donkey becomes invisible ?!?!

To reproduce:
1. Build railroad to distance of at least 15 chunks with powered Powered Rail at ~30 block intervals and unpowered Powered Rail at the end.
2. Load donkey into minecart and set it moving.
3. Follow behind it in your own minecart and eventually donkey/minecart will reverse direction