This is my first attempt at creating 5.1 AC3 files, I'm using Sonic Foundry Soft Encode. The resulting AC3 file seems good (at least if I open it up in Soft Encode it can extract all channels with no problem).

When I burn the video using Adobe Encore, all I get from my DVD player is 2 channels. It seems to have even taken the back channel and put it on the front. I suspect this may have something to do with Encore?

The AC3 audio file shows up in the timeline with "Don't transcode" so in theory it's DVD compliant.

Any thoughts? Should I just try some other authoring software?