I think he is saying he'd like to solve the problem so he can get rid of the rerailers...
Collyn - look at where the wheels are coming off the track. If all cars jump off at one spot - it's the track. If only certain cars do it, but do it all over the layout, then it is the car(s).
If you do not have an NMRA gauge, you should get one for your scale. It will let you check all the stuff that should be in gauge - track, turnouts, points, wheels, etc.
Another thing that can lead to derailments, evn if everything is in gauge, is weight. Properly weightin gthe cars (as per NMRA specs) helps to keep them on the track. If you have underweight or light cars between the loco and some heavy cars at the end of the train, the light cars can be pulled off the track on curves, since the train will basically try to make a straight line between the loco and heavy cars.
Hope that helps. Post more information on your investigation!
Andrew