Well, there's a difference between that raw retail part you bought, and an identical mobo in a pre-built PC. A guy I knew did IT at a big paper in... Annapolis, if I recall. Several years ago, they upgraded to shiny new all-in-one PC's all over the newsroom. I don't remember the brand - either HP/Compaq or Gateway, probably. Anyway, a few months in, they start failing, one after another. Turns out a bunch of them had components that had all been in one shipping container in a warehouse - and that container was under the leaky spot in the roof. By the time they were built, the boards had dried out and nobody noticed, but the damage had been done.
Your retail part, on the other hand, has been in its happy little shrink-wrapped box from the day it was born.