gonk,
I don't think that the 950 is fully "teachable". My 950 will operate as yours does: If I set my 950 PLIIC+CR (or PLIIM+CR), I get PLIIC+CR a dolby digital 2.0 signal or if I use the analog signal. When I switch to a 5.1 source, I get DD+CR-C get that format with a 2.0 source. This seems to be the most sensible way to leave the 950.
But lets say I'm watching an analog station CBS channel 2 and switch my 950 to 7-channel stereo.
Then I change channels to HBO and I switch the input to coax2. The 950 tells me it is getting a DD 2.0 signal, and if I change the volume, the 950 tells me it's processing in PLII-C.
Then I switch to Stars. The 950 tells me it is geting a DD3/2.1 signal. Change the volume, and it tells me it's processing in Dolby Digital.
I switch back to HBO. The 950 tells me it's getting a DD 2.0 signal. But now when I change the volume, it's reporting that it's processing Dolby Digital.
Back to channel 2, back to analog. And now it's procesing PCII-C.
Meanwhile, the Pro-Logic handles different feeds very differently. Many of the sources totally collapse almost totally into the center channel. But some are handled much better. And although PLII is better, it's still so variable as to be annoying. While watching the football game today on CBS's analog feed, the 7-channel stereo is just a fuller clearer presentation. PLIIC+CR is a bit more muffled and it's harder to hear the announcers.