Oh no, you did not heed my warning about how hard it is to re-assemble in your original post! But wait, did the cable just come off while in operation?
I wanted to mention in you original post that the chip might be the end of the regulator unless you replace the roller which is why I suggest a call to RegulatorUSA.
Did you call the regulator guy in Brooklyn to see if he sells just the rollers he uses?
I think the cable will still jump off the roller if the chip is not fixed. Reason being, the cable is under great tension as you found out. The cable itself has a tendency to want to recoil naturally so as the cable moves around the roller, the cable twists, as it twists, it will jump off the roller. Remember, the cable is nothing more than twisted steel wire and twisted steel has the tendency to twist in the direction of the winds.