1. You track texture must run from top to bottom of texture, not side to side.
2. Make a white mark on the top of the track so you know which way is up.
2. Select Front vertical face of the front vertical section of track
a. Go to 'Look at face' window.
b. Select the other side of this section of track
3. With the track 'up' texture as normal.
4. Now move down the track towards the floor. Keep the 'up' side of the track facing towards the section you textured last. A some point in O2 you will have to invert vertical the track to keep the 'up' side pointing at the previous texture.
Keep doing this and it should work fine. When you are finished reedit your texture to remover the 'up' marker.
Its a pain in the bum btw.