No Audio detected while trying to encode from DVD source

Hi there,

I am a composer, trying to encode DVD's of my past work so I can edit a showreel. I am having problems with some encoding some DVD's as for some reason, Adobe Media Encoder clearly states that there is 'no audio' on the clip, however there absolutely IS audio on the clip when I play it in VLC or Windows Media Player. I'm completely stumped. Have tried deleting cache, installing Premiere Pro trial edition, and tried encoding on two different computers, to no avail. On the tile before the show starts I do notice that it says 'Audio configuration - A1 Stereo Final Mix L / A2 Stereo Final Mix R / A3 Stereo Mix minus narration L / A4 Stereo Mix minus narration R.' Could that be the issue? That because there are more than the regular two channels of audio it's confusing AME?

Thanks for your time, Alex