I take it then that your PS3 is one of the early, 60gb models - the later 40gb & 80gb units had this feature stripped (as well as the dream engine for playing PS2 games).
Most SACD's are actually hybrid discs that have a "normal" CD layer too - you would need to ensure you were actually sending the multi-channel data to your BS3 (I'm not sure how the PS3 handles this, presumably multi-channel PCM, but I don't know).
...........................and then the speculation starts, you sound like you have read the thread that "raged" here a month or so ago. There is a question mark (not to mention considerable disagreement) about how comprehensively the BS3 handles multi-channel "high-"definition" audio.
I fear it is all about to break out again
Generally speaking, you aren't learning much if your lips are moving.