I've been trying to call the person I bought it from was reportedly moving to Alaska in a hurry (that's why the price was so right - no worries - he had the original bill of sale!). I haven't had a chance to look at it again but I think the 'racked' assembly is the leading theory I have now. However, I thought the rear beam brackets on the beams were adjustable so you could take out any misalignment there.