A few of these clips were cut/replaced in the 2004 airings (the ones currently used). Here are the changes:
Show 3976
"What's the Good Word? A Plan, Plan, Plan song" is replaced with "Picasso Faces Look at Happy" cartoon.
Show 3977
"Noodles and Nedd: Leaf Paining" is replaced by "Girl's Day at the Park" animation.
Show 3978
"Some Ducklings Splashed at the Water's Edge" was cut.
"Chinese Acrobats Demonstate 5" and "Stick-Figure cartoon about 5" were replaced by "Penguins Five" (definitely a better change; this film's from 1969!) and "Woman Orders Five Tall Things" cartoon.
"Lady discovers monumental N" is cut.
"Large 'N' in Pool" is inserted after "Little Boy wrote a song about his baby sister, Elmo loves it".
Show 3979
"Suzy Kabloozy Introduces Prairie Dawn and Big Bad Wolf demonstrating 9" (aka Suzie Kabloozie Judge #9) was cut.
"Making Paper Airplanes" is replaced with "Kids Dance, Sing, Draw, and Act".
Show 3980
"The Martians Discover a 'U'" was cut; it was after "My Friend 'U'".