Hate to hear that, I couldn't imagine the distraught. I have the same racks and have noticed the hand knob threads backing out at the base as well. Takes a lot of hand strength to lock them down, I used a pair of channel locks on one of my hand knobs cause it wouldn't tighten. After seeing this post, I will be thru bolting my bottom base hand knob as well as the upper rack as well, get rid of that mickey mouse crap. Lot of money riding on these racks down the road, and most time to dark to see them when heading to the lake.