the Minecart derails when it runs along the powered rail

I created a rail link between two elevated areas and I connected them with the rails. As usual, near the powered rail I put the red stone torch and the rails lit up.

What it would happen is that when i put the minecart on the rail, it should complete the path without problems. 

The problem:

So, what happens is that when the minecart is on the powered rail it starts derailing and if I'm inside, i fly down.

I don't know what to do because that's the only part of the world where i found it.

In the pics below you can see the structure (1-5) and the problem (6-9)