My son & I built an N Scale layout using one of the plans that is in an Atlas Layout Book. The layout is on plywood (cookie cutter) with the track on foam roadbed. We are having lots of problems getting the trains to run smoothly. I have Rapido couplers. They uncouple contantly when going through a curve. The cars also jump off the track frequently, usually at turnouts. We are new at this. Should we switch to a differnet type of coupler? Are there any tricks to keeping these cars on the track? Thanks for any help or suggestions.