I had a rail station which ejects the player and recycles the minecart.
To hide the redstone the cart is taken down diagonally allowing it to pass through the block.
This worked fine until the release of 1.2.5 now the minecart gets stuck half way through.
I have attached an image showing the scenario.
- relates to
MCPE-17770 Minecarts can pass through blocks when on a slanted rail