Bad news, that can do some ugly damage to bike and body but it sounds like you did not get hurt. If the chain line is straight and the teeth on ring and cogs are good, then I'd say a tension problem. If not concentric, try loosening the chain ring bolts and tapping it around with a rubber mallet until you have even tension around the full crank stroke. Then torque down the bolts. You may have to file the chainring where it meets the spider if it's already a tight fit. I just sent back a brand new Campy Pista crankset back because it was far enough out of round that I could not get close to even tension. While swapping parts around to diagnose the problem I threw on a 70's NR road crank with the 42 ring mounted on the outer flange. It was dead nuts perfect. If Campy gives me a hard time about the return I'll have to bring this to their attention. Good luck
Otis Williams
Grants Pass OR