So I read the above post and it's filled with information. I'm still looking for good material to test this with however. I found from the linked posting:
"Watching Iron Man, the scene when he makes a return to the village near where he was held captive & starts kicking butt, the part where he takes out the last bad guys and the young boy runs to the side of his father. I.M. walks from left to right, and the sound pans left to right. I tried setting up the center speaker in every way possible, but the sound always did a “roller coaster” effect, dipping up or down to the center speaker, depending on its orientation."
From a review here of 5.1 Systems I got the Lord of the Rings Bridge scene (I can't spell the name of the bridge)
Are there more?