Well, we pulled in from out trip to Lakeport SP, MI. We had a great trip but the drive home with a 2 year old and 6 year old took FOREVER (about 12 hours with pit stops and eating and such). I was too tired to mess with the PUP last night, so I just left it in the driveway and went to bed. I woke up this morning and went to unhook it from the TV and noticed that the nut had come off of the ball sometime during our trip. I have no idea if it was the ride up or ride down, but either way, that could have been REALLY BAD! I guess I was just one good bump from losing the entire thing... Not the way I really would want to test the criss-cross chain theory. I just this serves as a reminder for everyone to check ALL the bolts, from the wheels to the ball!