I am using Vegas Platinum 8 but also tried with Platinum 9 with no success. Clips come from an AVCHD (Sony HDR-TG1E) complete with surround sound. Edits go very fluently and rendering to HDV mpeg2 goes very fast, but I end up with stereo rather than 5.1 sound. I can use the "Make Movie" menu to render onto a DVD with 5.1 (AC3) sound via DVD Architect. The DVD plays fine with good location of the various tracks in a home theatre. Tried it speaker by speaker, excellent. But this is SD. I have not managed to find a template or a setting that can render to hard disc giving both 1080HD and surround sound. I think I tried all the templates that make sense. Please note that I can render the AC3 sound easily, but separately from the video. "Make Movie" simply recombines this file with the SD rendered video file and sends it to DVD Architect. But I am not interested in a DVD, nor in SD. I simply want to combine the AC3 file with a 1080 HD video file and save the m2t or whatever on a hard disc.

On another board I found a suggested work-around. To render the sound onto AC3, use an external program to convert to .wav, recombine using Quicktime somehow and re-render to mpeg2. Surely there must be something in Vegas? The Sony camcorder I tried already comes out with surround sound, and Sony has sorted out how to edit the AVCHD (presumably the difficult part), complete with fast, smart rendering to 1080HD mpeg2(m2t), but somehow forgot about the multi-channel sound. Editing by adding more sound channels also goes well. Neglected how to render the AC3 and HD together? Really?!