Maybe if i put the model for you to play around you can help me?
I have problems with disp maps in max 6 too. I am testing the pixologic head and dont work.
The steps are exactly the same that cg18 is described:
- inport the head
- apply meshsmooth
- apply disp map (rotating it)
But dont work.
Please help!!!
–Thanks Chaos… 
i’m waiting your tut–
Well. If we’re talking about creating iterations with meshsmooth or tesselate and then applying displacement modifiers then the renderer shoulden’t change anything since the object is what’s changed.
But when it comes to micropoly displacement the renderer uses the material to change the geometry. Here it’s important what renderer and what settings used… And I just can’t get mental ray to do the displacement whitout banding…
Since micropoly displacement is a lot faster and gives much better results I don’t understand why the tutorial in the practical guide uses Vray’s displacement when mental ray is included in max 6…
Well, maybe they used MAX 5.
I still stuck 
Not to rub salt in a very old wound, and I hope you’ve since resolved all your problems, but it seems to me you answered your own question.
I have recopiled some tips or comments in text files from other threads here in the forum:
hope this help
Andreseloy