It's not just the chinese tires that pop without warning, the chinese valve stems do too. Discount tire is recalling zillions of Dill valve stems installed by them:
Discount Tire Recall
Safety Probe
I apologize for duplicating this if somebody already posted it, as I didn't see it. We just got notice today for our Expedition. Fortunately our pressure sensors are built into the stems so they didn't replace them when we got tires.