If I rememner rightly, this was your very first problem Choosing PCM audio on the first screen of the TMPGenc wizard meant you ended up with elementary streams (seperate video and audio), which you couldn't use in your Ulead DVD authoring app .
Apologies, but I'm from the UK and every single DVD I've made using MPG audio has worked on a whole host of DVD players. So unfortunately my experience is based on this (but I've learnt a new thang now!). The DVD standard dicatates at least one layer of PCM or Dolby Digital audio - this isn't necesarily to ensure it plays, but to ensure it meets the quality standard of the DVD medium (as I say almost all PAL players support compressed audio - wierd, huh?). In fact DTS audio isn't a DVD standard, so you'll see an extra layer of PCM audio on DTS encodec discs.
It seems that PAL players are happy to play compressed audio, whereas NTSC players in the main require uncompressed audio. So you'll have to choose Linear PCM audio in the first wizard screen of TMPGENC.