Depth of field & Transparency - Focus behaviour

Hi Guys,
take a look at the sphere in the bottom left.
In the 2 images i’ve just changed the material.
Why when using a transparent material the part of the sphere in the second image has blurred edges on the top? (it is out of focus as the stuff on the back)

Thanks a lot!

enable: output velocity in the material specs
and uncheck Render After DOF

i have the same issue. I use a master material and if I change the settings there it affects all oother instance materials in the scene as well and thus the shadows change. My soft key suddenly produces a very sharp raytrace shadow.

is there not something that does the dof solely based on actual depth of an object and with the correct layering in mind?