Argh client is gonna be walking through my door in a few hours and this is driving me nuts.

I'm not new to AE, been using professionally for a while, but never encountered this before and dont know what the heck is going on, I really really hope someone can help me here. Thanks in advance.

I've got a pre-composition which is of an actor on a green screen, i've keyed out the screen and used masks to cut out 'the rest of the room'. I've then put that pre-comp into a 3d composition, when the camera is close to the pre-comp it looks fine, but as the camera pulls back the almost looks like the masks used in the pre-comp are changing position, because the pre-comp is slowly having it's edges crop into the image. Basically what is happening is at first I can see the whole figure of the actor, then as the camera pulls back his feet start to dissapear and then his legs. It looks like i've animated a mask to slowly crop the pre-comp.

There are no intersecting layers. Im in 6.5 pro. Using advanced 3D. Continually rasterize is not turned on for the precomp.

I've searched forums and sites and havn't found anything to help. Any advice would be very appreciated.

Thanks,
Anthony.