[lexaudio]

Dude,

you are not understanding. The audio is not an audio file. It is an encoded file. Most likely and AC-3 file.

So when PT is trying to determine what file type it is, it is saying, "This is not a proper audio file".

AC-3 is an encoded file. It needs a decoder to play it. Quicktime has this built in. So Quicktime is decoding it into 5.1.

AC-3 encodes to a stereo file, but if you were to listen to it undecoded it would be nothing but noise.

Pro Tools will not split an AC3 encoded file into audio files.

Final Cut used to have this thing called A-Pack that would take an AC-3 file and convert it into split audio files.
Sometimes it would work, sometimes it wouldn't.

Try MPEG streamclip. If I remember, it would decode AC3's into split files, but you have to run it for each set of pairs.