I'm rendering a NURBS globe with the maya renderer, to an IFF image sequence, and I keep getting these horizontal bands of half transparency across the entire frame. The bands vary in thickness, and change with every frame, so it's not a geometry problem, also. I've tried different shaders, so it's not a shader problem. It seems to come about in post-processing (It's an HD frame size with 2d motion blur turned on.) Any suggestions? I'm using Maya 7, by the way.