max 2011 vray 2.0 x64 displacement problem

Hi guys. have a scene here with a 2d displaced floor and a 3d displaced brick wall. there are dirt maps all over the place, and a vray fur to put grass between the pavers. other than that its a simple scene with about 5 objects in.

it was rendering fine all day, until i detached some faces from the wall object. next render crashed with an unhandled exception.

if i turn off displacement in the render settings it doesn’t crash, but if i turn off the 2 displacement modifiers manually, it still crashes.. strange. ive tried merging to a new scene.. doesn’t help.

displacement modifiers are not set particularly high or anything, and as i said, was rendering quite happily in about 3 gig of ram up until about 20 mins ago..

any ideas?

ahh and the disp. maps are in the modifiers, not in the materials..

lol ok forget it and delete the thread. there -was- a disp. map in a sub material on the faces i detached. was causing problems somehow. no idea why but killing that fixed it.