Crash90,

What I did was install the screws through the Petemodel non-knurled backplate, the put the prop on. I tightened the nut some, and the screw heads left impressions in the back of the prop. I then center-punched the impressions, and drilled tight clearance holes in the prop to go over the screw heads.

80 flights so far, no slippage, and my prop has not exploded. I've tried four different props, will no ill effect.