Fluid Particles missing vector blur in cycles?!

Hi,

I have a scene of a hero using a shield to protect himself from a
stream of water.
The fluid is hitting the shield and is generating fluid particles.
I have “generate speed vectors” active and the vector blur works
on the fluid itself but not on the fluid particles.
Is this a current limitation of Cycles or a bug.
It works with Blender Render.
I’m using version 2,78.

thanks for your input,

Ralphi

I am having exactly the same problem. Maybe Blender loads all the particles for each frame individually and does not know which particle in frame 1 corresponds to which in frame 2