I had something unusual happen this weekend while viewing a Blu Ray copy of Lord of War. This disk has a 6.1 discrete DTS-EX track, and while using it I could not change the dolby modes. When I pressed the Dolby button, the 990 display flickered for a second to what I think was dpl-iix movie (hard to tell since it only flashed), then went back to DTS-EX...think it may have even said discrete DTS-EX on the 990 display. I don't remember this happening with other DTS-EX dvd's, like say Gladiator, will have to verify it. Wonder if this is a bug in the 990, the way the 990 should behave, or related to the way a PS3 is sending the audio track over an optical connection.