Ok I am using
Coretemp and it's idling at about 35 deg C per core. Even under load it's not maxing above 45C.
Now I have the ninja copper

and I put that in, I was very careful to make sure of good contact with the IHS of the chip. It's idling around 32-36 deg C now even after several hours and it's been a warm day. The base plate is much bigger and has a nice and shiny machined mirror finish contact surface. I've stepped the processor down to run at 1600mhz and still problems but anyway if coretemp is accurate I'm guessing the problem is not with the Ninja but as you say probably the mobo, chip and Vista64 simply don't get along.
Now I have put heat spreaders on the ram and a ram cooler plus an extra case fan and I've switched off the extra graphics stuff with Vista to run for performance only, so far so good fingers crossed.
Thanks anyway for your concern and your follow-up email that was very thoughtful.
Cheers.