I have a number of layers strewn about in z space, and I want my foreground layers in focus and my background layers out of focus. But for the life of me I can't seem to find the right combo of aperture / focus-distance / blur level. If I increase the aperture, some of my foreground layers go blurry. If I lower it, everything in the background comes back into focus. I can't seem to create a window that keeps the desired FG objects in focus while throwing the BG objects out of focus.  I wonder if I'm using some non-standard values, or perhaps i'm asking for something that's not possible.

In this screenshot, I'd like all the orange X's in focus and all the green circles out of focus:
http://i.imgur.com/g54hfxc.png

project:
http://bit.ly/11qnLnj