Ok, i see the problem now. It seems CLine adds some type of offseting, which is not interpreted correctly by RailClone.
Please, try this:
1) Once created, apply to the spline: Utilities->Reset XForm and collapse it to Editable Spline.
2) If the RC object is already using the spline, click General->Spline->Realign.
Checking the code, i cannot find any difference between RC 1.4.2 and 1.3.0, in the way them handle the path. Perhaps the problems is random, dependly of how CLine creates the spline. Anyway, the above procedure should solve the problem.