First off if your track is not sitting level attaching 2 flat pieces together you definitely have a binding problem. The rails should be flush or even a little back from the edge of the track. If it's sticking over the edge it needs to be filed or pushed back. The rail just pops out of the track but if not done carefully you can bend the rail. Are you using the track clips to hold them together? If you want to fasten the track down I would just fasten the curves down because that's where your pressure is gonna be and let the rest float. That's what I've done with mine and it works good.
Dave