the opening where Bill is in front of the brick wall thing with the hip hop jazz music. On N@N they do not show lisa bonet or the guy that plays martin. but when i went to that italion cosby show site they had that opening with lisa bonet and martin in it. they also showed the rest of the cast doing some different dance moves than the one they show on N@N. Does any1 know why?

I'm not sure of the exact reasons, but the opening sequence you describe was originally used for the 7th season and included Denise and Martin. After a few episodes, it was dropped and replaced with the 6th season opening sequence. When season 8 rolled around, they brought the "brick wall" sequence back, but Denise and Martin were no longer part of the cast so they were removed. Does this help any?