I have some (4 actually) divX files that I want to combine onto 1 DVD. I was able to make very nice .mpg files with hard subtitles on each which I can author into 1 DVD. Since my source only has 1 language that is an acceptable solution. But I have a little problem and a bigger issue awaiting me with other files ...

My little problem... The divX file has an AC3 soundtrack and I ended up with a .mp2 soundtrack. Should I have used passthru as the audio encode method to keep the AC3 sound?

The bigger issue awaiting me with other files... What do I do if there is more than 1 language? That is my source will have 1 video track, 2 audio tracks and a subtitle track? I can use ffmpegX to author each as a DVD and end up with 4 VIDEO_TS folders (each with the ability to turn subtitles on or off). I can even give each separate title number (ie 1 thru 4). But how do I 'glue' 4 less than 1G VIDEO_TS files into a single 4G VIDEO_TS suitable to burn to a DVD-R?