I've created a movie in iMovie, PAL format, High Definition, and set out to burn it to a brand new Verbatim rewritable BluRay double-layer disc using Toast 11. I have an old 2008 iMac with the latest OSX software. The encoding phase took more or less forever but when it finally started writing to disc the burn was interrupted by a message to say there was a burn error and the disc was unusable. I erased the disc and tried again, with the same result. It seems to me likely that the encoding has introduced a fault and that further attempts to write to a new disc would be futile. Does that sound right? Can it be the BluRay disc that's faulty, and if that's the case would the error be likely to recur at the same time and place? Or could the original movie file be the problem? I guess my best option is to try re-encoding the project but if anybody has a better idea please let me know ASAP.