TSX off, no shadows on certain trains

On my laptop, which is not very powerful in the GPU with only a nVidia 9300, I have to play Railworks with TSX off and only a litte AA to get a reasonable performance.
With some eye-candy still on, I noticed not all trains are casting shadows, notably my new SD45's.
How do I enable shadows?
With some eye-candy still on, I noticed not all trains are casting shadows, notably my new SD45's.
How do I enable shadows?