We recently purchased a 21' Jerr Dan Rollback on a 05 Ford F650 chassis. It has been used for about 3 months when we noticed that the bed was bent in the middle like a banana. We've contacted the dealer who was going to get with the Jerr Dan engineers about 4 months ago. We are still waiting for a reply from Jerr Dan. The last we heard is that the beds hydraulics were not supposed to be able to bend the bed, so how else can you bend a bed.