Tire Valve problems of the 2004 GMC Sierra

On 7/10/05, while pulling my camper, which is a 04 GMC 2500hd, bought new to pull this camper, I experienced a flat r/r tire with-in 40 miles on the truck. On 7/11/04 I experienced 2 flat tires on this truck due to defective valve stems. After checking with other Chevrolet/GMC owners at campgrounds, there is a major safety problem with the rubber valve stems. I ended up having to have steel valve stems installed on the side of the road due to tire failure and replacing two tires that only had 13,500 miles on them. The service repairman explained that due to heat buildup on the tires, the rubber valve stems will not accept the heat, and fail. I had three failures in two days due to this, which could have caused a serious accident and injury.