From another thread, I believe you are using Vegas to encode, correct? What options do you have for Blu-ray, is there a "DVD Architect Blu-ray" preset available? Can you post your encoding settings? Maybe bitrate is too high, could be many things. As for audio and video being different lengths in Encore, that is a common issue because of bringing in a "muxed" file, meaning audio and video together. For Blu-ray, you should have .mv4 video and .wav audio (or .ac3 audio) as separate files.