dazb:Ok why was Dolby Digital 5.1 not on the blueray trilogy we had Dolby True 5.1 Hd but no Dolby Digital 5.1 except for france and spain. So i ended up viewing it through linear PCM. Yesterday the Godfather was on Sky HD Movies and guess what it was Dolby Digital 5.1. Which sounded great why Paramount could not have done 5.1 for the Boxset is beyond me. Id have been better of buying the Dvd Boxset seeing that was in Dolby 5.1 wont make that mistake again.
I'm assuming, since you want standard DD 5.1 instead of DD-THD 5.1, that your system can't handle HD audio - this shouldn't be a problem since your system should be able to decode regular DD 5.1 from within the HD audio track (am I right, anybody?). My system isn't equipped for HD audio and yet my Onkyo 506 manages to decode DD-THD tracks as regular DD.
I'm curious to know what equipment you have; you obviously have the capability to listen to PCM audio through your system, yet (again, I'm just assuming) it can't handle the Dolby TrueHD track properly (otherwise you wouldn't have a problem!).
Anyway, as far as I can see, if you just turn on the Dolby TrueHD track, pretty much any 5.1 system I'm aware of should be able to decode regular Dolby Digital from it.