I garnered a little trick to help renders in p6 - when you are in render settings reduce the bucket size from the default to about 22 that speeds the render up, seems to stop it stalling and also allows you to cancel the render if you decide to with out the whole darned lot crashing to a halt! Also unless you can see the back of an object throught the front ( ii if it is transparent or open at the front like a coat or dress) check the ignore back faceing polygons button. hope this helps