ah!  i have that room.  that's from good ol' ratracer, he kicked butt.

here's a pretty cool workaround that i had to figure out that has so far let me print anything i want.

turn off shadows on this pass.  the frame may still not render the whole pass.  no problem.  save that render.

then render with area render the next section, but go ahead and use the same dimensions.

you can render slices off of a gigantic scene this way and chop the good layers off.  then you don't have to worry about figs/objects in the foreground or background laying over each other when compositing single elements only.

then render the shadow layer and composite that.  you can render that smaller too if you need to and just increase the size when you composite.  i have recently been told that you should use "multiply" in photoshop on the shadow layer for accurate shadows, and double the layers if you want darker shadows. 

that bucket size was crazy man.

go that way really fast.
if something gets in your way
turn