Hi Eduard,
It seems the GrowFX object are not producing Motion Blur in Vray [2.3] ?????
I did a small Point Cache as a test and it worked fine that way although I would prefer to have the original GrowFX object do it so that Gigabytes of Point Cach data don't have to be produced whilst testing ...also the Point cache seems unstable at times as well.....where as GrowFX is rock solid.
Cheers
Jamie