doubts abt hair and fur in 3dsmax9

[nagzray]

I have this strange problem in 3dsmax9, i want to know if it is a bug or is there a problem with my hardware... i am working on an enviroment scene where i have a road winding through a hilly area as i have to show a landslide effect, now i have setup the particle flow for the rocks getting loose and falling on to the road, to add some realism i have some amount of blur to the falling particles, now i had to make the scene a bit natural so i have used the hair and fur modifier to generate some grass swaying to the wind on the side of the road, it was all fine coz i had done this hair and fur thing before i setup the praticle flow for the rocks falling, and it was rendering fine, but after the use of particle flow the hair and fur is not rendering at all, i tired a new modifier of hair and fur removing the old one but no matter what object u put in the scene the hair and fur doesnt render and the funny part is that i can see it in the view port, but when i render it doesnt render..now i tried merging the entire scene to a new file and there the hair and fur is giving this error message saying the "topology change detected on motion blur object" now if i turn off blur for the particle flow the scene renders without anyproblem including hair and fur but put back the blur and it doesnt render... is this a bug in max9 or is it the problem in my system??

[d.sign]

Only thing that I can advise you is to try and render things separately and merge the layers in PS. Or add a mask to particles and blur them in post work in PS...
I do not think that it is problem to your hardware, cause it would crash Max, but with such complex effects it may be better to ease up a bit and separate them to passes or do some post work effects...