This is really weird.
I am not sure if this is the reason but ...
Today I ran freescenebitmaps() on my scene.
Shortly after I noticed that when I do a render of the Perspective window, which in shaded mode shows
all textures, Render Production is not rendering all of the textures.
Now freescenebitmaps() may have nothing to do with this but it seems kind of coincidental.
Any thoughts?