Yes, it's possible that the rolling surface of the tire isn't perfectly round even though it's balanced. +1 for seeing if they'll let you test it out on your old tires/wheels, and if the problem remains you know it's suspension/alignment related. If it goes away, try finding a place that does Roadforce balancing on the tires as well as traditional balancing (with the Hunter GSP9700). They test the rolling surface under load while still on the machine to get rid of any possible vibrations. With these kind of tires, it can make a big difference. I had it done Friday when I put my new Michelins on, extra $10 a wheel and nice and smooth (up to 90 so far, further testing to come ). If you want to know more, go here: http://www.gsp9700.com/