I think the reason is because I'm using the crossing-your-eyes technique, so instead of the picture popping out at me, it caves in, IE the background is in front.If I was any good at the parallel eyes technique I would try that and compare the two. EDIT: just out of curiosity, what would happen if you inverted the colors used in the grayscale image? Do you think that would swap the foreground and background positions? It's worth a try.
What do you mean I need a life? =P Hm... Lives... Isn't that something that you get in Super Mario Bros? You know, those green mushrooms? That's a life, right?