download the shader workshops. you'll see how jcl uses a R32-bit TargetMap.

@BoH_Havoc: mine doesn't have that issue. i can't imagine what's happening, but mine works quite well (not the final result, yet, but the blurring of the R32-bit depth map in a separate map and comparing the results).

are you doing separate horizontal and vertical blurring to reduce the samples? i was planning on doing that if i find time today, but at the moment my shader (in a rather un-optimised fashion) generates the difference map in the same stage as the blur, so with no need to access the depth map later. i can't imagine why it would get blurred, though, if you have it in a different bmap altogether :S

julz