Here are some pics. I bought the frameset used. The drop outs seem straight and there's no indication that it's been bent. The rear derailleur didn't come with the bike but I bought it used. The cassette and chain is mine. I was previously running this cassette and chain on another bike - first with the original short cage 9 spd derailleur and later with a 10 spd medium cage derailleur that I bought when the 9 spd one cracked. No problems.
The only "funky" thing that is happening is that I'm running a Shimano crank - a 53/39. Otherwise, the whole drive train is Campy 9 speed. That includes the shifters, RD, cassette and chain. Other than this problem in the second lowest gear the rest of the gears all shift smoothly.