VPI record clamp

I'm a new owner of a slighty used VPI Scoutmaster. After reviewing the manual I'm unsure if I am using the stock record clamp correctly. When I screw it onto the spindle the bottom portion of the clamp seems to angle depending on where the clamp is on the spindle. As I tighten it down, the record warps a bit, then starts to flatten out. When I get the record perfectly flat on the outside edge, the center is not flat. Am I doing something wrong, or is this how the clamp is supposed to work?

A_L