No I think its a bug int heir post rasterizing system. I get it on my system (1.1g with 768megs ram and 27 gig HD) when I a fill up the scene (Downtown modelw ith 4 mike characters and 1 vicky character plus 3 or 4 cars). After about 10 to 15 renders it starts getting odd FX. I'm a graphics programmer by trade so I understand what they maybe doing in their system. I'm assuming they render their scene in a memory buffer using either a reverse painter's algorythm or a bsp tree (I don't think the use bsp trees) into a render buffer and a zbuffer. Then they take that rendered image (this is just the rendered polygons with lighting) and output each scan line through second stage filters like anti alias and perhaps shadow. They could either do shadowing during their render process or they can do it during their second pass process. I'm assuming they do it during the second pass process using the shadow maps as light maps for each scan line to filter through. Now here's why I think its in the second pass filtering instead of the poly renderer. 1. You don't see this effect in their preview mode. I'm assuming preview mode is basically back to front poly rendering with low res textures. Since this is probably the same routines used to renderer their offscreen buffer to setup their second stage rasterizing then I don't think its in the poly rendering. 2. Most of these FX are screen aligned and not polygon aligne or camera aligned. Again if it were a poly rasterizing bug, the smear would probably change direction as the camera or the shape changed. 3. Seems to be memory related which may not absolve the poly rasterizer but since post process stuff can be more memory intensive than the polygon rendering the odds are that its the post process. 4. These flukes do not show up in other render modes like cartoon or wireframe. If it were a poly rasterizing bug then cartoon mode or other modes would fail as well. This still could be a poly issue when rasterizing actual textures but its becoming rather doubtful. One thing you could try is turning off post process features like antialias, shadow and bump and see if this effects the outcome. Now I have seen other bugs that do indicate a polygon issue namely when rotating a scene with a really huge shape like a building interior. There I'll see polygons "spike" as though the vertex is improperly computed. This could also be an effect of their preview render mode if they are just brute force rendering polygons from front to back into a zbuffer or back to front if no z buffer. A long polygon cutting across the scene from back to from will tend to plop on top when it shouldn't, especially if they are using a gross estimation of poly position as s primative depth sort. My question is, do they dump the textures not used on a shape or are those kept in ram? For example, if I load 3 characters with different maps then delete them all, their textures still stay in my texture list. Are they fully loaded or are they just referenced? Poser won't let me use the same named texture from a different sourse saying its already loaded yet I can change textures in photoshop on the fly while poser is running and have those changes show up when I run my next render.