Guys, I finally broke down and bought the PCS10 work stand. I have a few questions though. The top clamp that clamps to the vertical tube tends to spin. I've tightened the bolts pretty tight. Has anyone had this issue? I have the same problem at the height adjustment (not the clamp but where it has a bolt). How tight do I need to make these? Seems like it should have a knurled finish to prevent slipping