Peter, I won't try to go into detail on the subject of tire inflation, been out of the business a few years, and don't claim to be an expert anyway, but there's a world of difference in car and pickup tires and tractor tires. Basically, the pressure listed on the sidewall of your tractor tires is the maximum to be used to inflate and seat the bead; has little to do with the pressure at which you should run them (and I know there may be some exceptions and if someone wants to correct me, feel free to do so). The pressure listed on the sidewall of your car and pickup tires might be considered a "maximum"; however, you can generally exceed that by 10% if the weight they're carrying justifies it. And, more importantly, you should NOT run them at less than 80% of the pressure on the sidewall. At least that was the rule the last time I had anything to do with the business.
In '91, while working with my brothers in their tire dealership in Alaska, we warrantied some Uniroyal tires. Every one that we warrantied (bubble between the cord and tread) was on 3/4 ton GM pickups or suburbans and were being run far below Uniroyal's recommended minimum, but within the minimum in the vehicles' owners' manuals.
Now I don't know any more about the Ford/Firestone deal than what was in the news, but I strongly suspect the same thing happened with them; never would have been a problem if the tire pressure had been kept up to what it should have been. And then of course I also suspect that incompetent drivers had something to do with it, too. I've blown (I meant in one big bang) both front and rear tires while doing in excess of 100 mph with no power steering and never had a problem controlling the car, but a lot of novice drivers will instinctively hit the brake, which is the worst thing you can do.
Oops, let me off this soapbox before it collapses./w3tcompact/icons/laugh.gif