I can't help you with your problem exactly, but try rendering to an image sequence (TIFF, TARGA, PNG, etc.) so that after it fails, you can re-render with the 'skip existing frames' option selected. This will skip the frames that rendered successfully, allowing you to continue where you left off. Eventually your project should be completed (if it fails on the first frame when you re-start, then you know something's up with that particular frame. We've got a video that won't burn completely to disc in Encore, and it always stops on the same frame).