I would try render to screen - you can make it bigger than your screen if you want to - you will have to pan around at the end to find the save button - and you can see what is happening and if you see corruption like this you can stop the render and investigate. Also, if you are using Vue 4 then I think you must also have been using ultra to get a render time that long. Try broadcast - I cannot see any difference worth bothering about between that and ultra. It may very well be some other program interfering. When I got Vue 4 it would not render transparency properly. My vegetation leaves all had black surrounds where the transparency should be. After countless emails between myself and e-on help, lots of enquiries on this and other forums, I decided to turn off every program I had running in the background, virus checker, zip magic, firewall and so on, and then turn them on one by one to see if I could find a culprit. It turned out to be Keyboard Express. I have now switched to Typeitin which does much the same thing, and uninstalled Keyboard, and Vue 4 is perfectly happy. If you render on screen you can see if this corruption is happening, and conduct similar experiments. If it happens in every image you do, it may be that something like your virus program is conflicting. If it is just this one, then it may be this file is corrupt and the quickest solution would be to start again - infuriating when you have it just as you want it. Hope you sort it out.