AI Train crashes

[chrisjsayers]

My train is sitting on a spur line waiting to head south. I have set up an AI train to pass on the main line adjacent to the north. As I start my train the AI train derails. If I let the AI train get a few train lengths ahead and then start my train, the AI train will stall. The spur line I am on does not connect back to the main line. ( except behind me ). I have to wait for the AI train to almost dissapear before it will continue when I start. Can anyone help ?