particle skinner and motion blur

[chris_img]

Hi, im having trouble getting particle skinner to render motion blur properly.  I am using vray with the duration set to 1 and 25 fps.  So using the equation from orbaz:

"

Sustain Topology - When on, you can set a time limit for changing the modified object's topology. This is important when rendering with image motion blur; otherwise you can safely ignore this setting.

• Interval Ticks - The time interval (in ticks) during which the topology holds its consistency. The default value is 10; this is usually sufficient for the default scanline renderer. For example, to calculate motion blur, the default scanline renderer takes two snapshots of the object geometry four ticks apart to define the overall geometry change.

  Note: In 3ds Max, a tick is a very small time interval, of which each second contains 4,800. In order to calculate the Interval Ticks value for a particular renderer, you need to know the Motion Blur Duration setting. You can use the following formula: Duration*4800/FPS + 1, where FPS is frames per second value. For example, if Duration value is 0.4, and it is NTSC frame rate (30 frames per second) then the Interval Ticks value should be 0.4*4800/30 + 1 = 65."

  I get 193, which for some reason turns the blur off every 3rd frame, anyone had this problem before?