01 DeVille stalls??

I have an 01 Deville with 29K miles on it, and it will quit running occasionally. If idling, it will shut down like you turned the key, or while driving in traffic, etc. I?m thinking a crank sensor, as I?ve changed fuel filter, no codes stored, etc. It?s under warranty, but they want to give me a song and dance about diagnosing with no symtoms. Just wondering if this type of problem is widespread, or is an isolated incedent among millions of cars produced?? Anybody else??