For me, its impossable to render to a different aspect ratio. It update the width if you adjust the height and vice versa. You guys should try it.. Only thing I can think of being the problem is when you render to a larger size poser shows you it at 72 dpi. So your image might be larger then the screen and you need to scroll up or down. Sandoppe, render one in the preview window, and then your final. Then with an image program (not poser) compare the images.