The Audio TS folder is supposed to be empty, it's a leftover compatability thing that some players require. Your audio is part of the MPEG2 stream. If the files have audio on your PC, then there's a possibility that your DVD player is not able to decode. What audio format are you encoding on the DVD? Is it PCM or AC3? If it's PCM, it will only output through the stereo line outputs of your player.
BTW, if you don't mind spending the $, TMPGEnc-Author is a much nicer authoring program, and it doesn't re-encode MPEG2 like NeroVision does.