I attempted to "Share", out of FCP 7.0.3, an 85-min. HD film I've been working on but got a "Share Failure - 3X Quicktime error" message after it had been chugging away for nearly 5 hours. Earlier, I tested my external Blu-ray burner (OWC Mercury Pro) with some 1-minute clips and it worked fine. My IMac is running OS 10.6.8. Any help would be greatly appreciated.