I'm not sure about the problems that the monorail has had but, I just had to respond to this. My 3 year old DS is in love with the Green Monorail. Don't ask me why, I don't know but, In January we were there and he insisted that he would only ride the Green Monorail. Well, obviously that wasn't alwasy possible. One night after spending all day in the Magic Kingdom we went to get on the monorail and the Pink one showed up. He protested but I'm bigger than him and I won in the end. But from the moment that we got on until we got off he wailed the entire time. Everyone in the car with us tried to help console him. They gave him candy, danced, sang, everything. We pulled into the CR and he started to calm down until he saw the passing monorail and it was light green. His screams got even louder!
This is too funny. My son had the same meltdown when he was 5 but about the red monorail! We are heading to the world on Saturday and hope that now that he is 8 we wont have the same problem.