Well, it appears taht you've already done the things that occur to me, but if you want to double-check... Make sure that the player isn't downmixing for some reason, check that the disc is multichannel (there are a lot of stereo SACD's out there), check that all the connections are good, and make sure the 950 was set to surround processing (the 950, not the player, which I think is what you meant).