Ok, I think you're missing something. I've got XMen and Star Wars...they are all 6.1 matrixed. Note that matrixed means the 6th channel signal is embedded in channels 4, 5. Skip to the last paragraph if you won't accept this.

There is an issue with Dolby-EX. You often have to turn it on manually, perhaps you need to try that. This is due to Dolby being so slow to put out the codec for receiver and DVD mfgrs to use. It ended up a big ol' mess. I now play with every matrixed or 5.1 movie. The only ones I let go with auto are the DTS discrete movies.

Ex: There is a huge difference in the opening explosion scene in Star Wars 2. When the flames go straight over the viewer, the 6th channel is very different from the side surrounds.

If you are simply looking for discrete only, notice what I said in my first post. Dolby does not have a discrete 6.1 format. Only DTS does, and only some movies, which are pinpointed on the list at their site. Read it carefully.