We just purchased our first Hi-Lo and are trying to figure things out. We have a 2401TD. We have only raised and lowered it about 4 times. The last time I lowered it, I heard a "crunching" sound. I saw that the wooden support that runs the width of the trailer at the bathroom had hit the top of the refrigerator. It just barely caught it and just shaved off a few splinters, but it was still disconcerting. Can anyone tell me why it did that? The trailer is perfectly level. Thank you for any help you can give me.