You may have noticed--the YouTube channel that once supported this website has been terminated. Busted for copyright violation. So any post that contains a video that's not working has been affected by this development.
One hopeful note out of this--rather than originating from the previous owners, Fox Home Entertainment, these violation notices were filed by Warner Bros. Entertainment. I can only hope they were going after these videos because WB is planning some sort of full-series DVD release sometime soon.