This might not be an FvwmBacker or fvwm-root problem but please help anyway if you know what’s wrong.
If I set two different backgrounds on different pages, I get this annoying “flicker effect” when I move from one page to the next: background 1 remains for about one second before background 2 loads, and then background 1 comes back again (!) before background 2 loads a second time after yet some delay.
I’ve tried using various images of different colour depths and sizes, but the problem remains. (Not retaining the pixmap didn’t help either.) The most odd thing, which makes me doubt that this would be a problem of resources, is of course that once background 2 has loaded properly, background 1 nevertheless shows up again for a second or so.