The fix is upping the Pixel Samples in the render settings.  The manual says 3 is a good default, but trying it out, 4 samples were superior to 3.  All other settings are identical to the ones I posted above.  You can lower this setting as you get closer to your subjects, but if you've got a scene with objects at very different z offsets from the camera I think you can't go lower than 3 (well 4 for me).  I didn't notice an appreciable increase in render time going from 2 to 4, but the entire scene here only took between 3 and 4 minutes to render total, so the impact may be greater in a larger/more involved scene.  I don't think there's much you can do about that though - aliased pictures look crummy so don't waste your time turning out crummy images to save yourself a pixel sample.