Video should now be online, btw what you set the displacement setting to on the shader in Maya will have no effect on what you see in Maya this is just to help you visualize the displacement in Mari.
If this does not solve your problem export just the house and roof geo and the displacement map from Mari and i'll do a proper breakdown of it for you.
All the best
David
From a readers' Q and A column in TV GUIDE: "If we get involved in a nuclear war, would the electromagnetic pulses from exploding bombs damage my videotapes?"