I am copying some movies strictly for travel playback on my portable, so 5.1 isn't needed. On some movies I have found that there are multiple Dolby 2 audio tracks. In some cases they are labled as director's commentary, but in others not. Is there any way to accurately predict which track is the commentary and which is just the soundtrack? It seems that the first one listed is the commentary - is that true, or just on the couple I've encountered?

Thanks!