skoal said:

... the *1st* Warner DVD ... the MGM DVD release contains the directional sound/panning ... the Warner DVDs contain the "I read you" line that's missing on the MGM DVD.

I received your PM and thought I'd answer it here. "Yes" to all your above excerpts. If by "directional sound/panning" they mean it for the dialogue, then, yes, the dialogue does sound like it's repositioning and taking the ambient sounds with it. However, the music sounds like normal stereo ..

Note that both DVD's show extra audio options, which cannot be selected in the computer media player (indicated in red). However, these options DO NOT show in the DVD audio menus at all (and hence cannot be selected there, either). Strangely, the 1998 MGM DVD omits H.A.L.'s full dialog (again indicated in red) while the 1999 Warner DVD does not.

Thanks for pointing that out! I'm still learning ever more about this movie.