I'm just gonna throw some ideas on the table... I once had a problem where Poser rendered part way, then rendered garbage for the rest of the render. I fixed it by clearing up a lot of space for the swap file and then defragging the hard drive. Not sure if this'd work for you but I suppose it couldn't hurt. Do you have plenty of HD space for the work file and/or the Windows swap file? What video codec are you using to encode your animation? Perhaps your video codec set-up got screwed up somehow and they need to be re-installed...