Just got three of these coaches from my LHS and none of them stay on the rails! I'm trying to figure out why so let me give some details... I'm using a Kato P42 modified with the Kato long shank coupler to pull them. 11.25" radius turns (which I know is tight). Trying to pull two Phase IV passenger coaches and one Phase IV baggage car. None or the wheel trucks bind or stick throughout their side to side movement. The odd thing is that I run 85' Bachmann Amtrak coaches with no problem (after changing out the couplers from rapido to a MT knuckle to hook up to the Kato P42 and LifeLike F40's modified with MT knuckle couplers). And I can run Kato passenger cars trains as well as other Con-cor 85' passenger cars without a problem. It seems to me that the amount of travel on the passenger trucks is limited by some plastic molding on the car's body so my first fix attempt will be to shim the whole truck assembly ever so slightly to clear it. If that doesn't work I'll try switching out the fixed knuckle coupler that Con-cor uses with an MT coupler. Finally, I thought I'd add some weight to both ends of each car over the trucks so they would be less prone to jumping the rails when rounding the curves. My question's are (1) have I forgotten any possible "fixes", and (2) has anyone else had this problem with these current Phase IV cars?