Maya Animation :: Reflection Blur In Mental Ray Does Not Animate

I am hardly trying to animate a fractal texture applied to mental ray reflection blur value of a blinn material. I keyframed the time value of the fractal: 0 for the first frame and 5 for the 180th frame(the last frame of the animation). If I batch render the scene all the frames look identical. If I render several frames in Maya render view by jumping from frame to another frame I get the same result: no change of texture. But, if I play the animation before rendering a frame in render view they look different that is I have an animated texture. I wonder why the texture does not animate? Amazingly, the fractal preview does animate! I tried to set the maximum value for time, that is 100, I changed the Time Ratio to the square root of the Frequency Ratio with no effect.