Hey Dave,
as far as i know, this is not possible. I have this problem too (Brushed metal logoplate with alphamasked logo stacked on top).
So, to answer your quastion in the thread title: I don't think you're stupid. And if you are, i am too ;)
Maybe meanwhile there's a solution for this. But if so, didn't hear of it so far. Did you try to use the corona decal object, maybe it works there?
Greetings,
Moritz