Vray motion blur problem

[larex]

I am reffering to motion blur, I dont understend how it was done but with vray 2 and fumefx 2.1 when i turn on motion blur on vray in rendering rolout the motion blur was rendered. It it was fake image motion blur it doesnot matter but it worked. Now when i try everything (like turning on image motion blur in object properties) or adding motion blur in envirinment/effects rolout it is not working at all..