Thanks for all the input. I really don't know what to attribute the wheel problems to.
Chaadster, as far as riding technique, I do wonder if the technique of weight off the back combined with the speed and hitting small bumps (unavoidable patches that span the lane, cracks that span the lane, etc), is part of the problem.
I always descend with my weight way back - is that putting even more pressure on my rear wheel than if I stayed more over my saddle? I have not had an issue with the front wheel and it's got 16k miles on it - original for the bike.
As for hopping - I do it if I need to, but not at 40 mph.
I may try 95 lbs in the tires and see how that goes. Just ordered a new wheel set yesterday.