Had several good replies to VAF post. Posted following after my trip to the airport:
Spoke with Mike at Sensenich this morning. He suspects I have one of the bad hubs, and gave me specific instructions on how to test for it. He was VERY helpful and promises a quick turnaround if I send the prop back. I will have to send the whole thing blades and all, so he can personally check it out.
This afternoon I went to the airplane; First checked pitot alignment, blade tip tracking, and bolt torques (with a different torque wrench). All within specs.
Then checked for blade movement as instructed. One blade has a nearly imperceptable, and yet real, movement fore and aft. And - it takes quite a strong pull on the beefy part of the blade to make it move.
In the AM I will call Mike back for shipping instructions. The bad news is it looks like I got one of the bad hubs. The good news is that hopefully the mystery will be solved and I'll have a new hub before the really nice flying weather gets here!
Tomorrow after I remove and pack the prop I'll post the serial number of the hub.