I noticed in a saw review that Rigid table saws don't have a blade height lock. In shopping around, I noticed that all the other saws have a blade height lock. The adjustment on the Rigid seems prone to turn if vibrated and this is of concern to me. I'd hate to have it sink even a small amount when doing a six foot dado. I suspect negative comments will be rare here, but why is there no blade height lock? Has anyone had any problems? I have to agree with the reviewer that this is a potential problem.