I tore apart half my upper level of track this morning trying to figure out why the track keeps getting kinked and tossing my cars. I was just about convinced that the trestles were more trouble than they were worth when I found the culprit. I have an old "vintage" set of graduated trestles for the rise and fall of my upper level. These have steel track clamps that the track just sits on and gets screwed down with #4 sheet metal screws. To finish the turn out, I needed extra trestles so I ordered a new set of raised trestles. These have plastic track clamps where the track has to first slide into a small groove and then be fastened down with screws. I guess not being in the grooves was just enough to hink up 4 sections of track in the upper level so that nothing was running right except my smallest, lighest trains and the trolley. This is what happens when Lionel doesn't put directions in the box. But I think it's all better now.