A/C was OFF, but we were running the fan for a little heat and defroster action.

I have heard of this "plugged drain" before, when researching the stinky A/C. Can anybody give me a location of the drain outlet, and tips to check for blockage?

It seems to me that this COULD be related... If the big stink comes back in a week or two, then I'm REALLY gonna ASSume that they're related.