Arnold Johnson was the original Fletcher and was replaced by Whitman Mayo. Both were born on November 15th 9 years apart.
Fletcher is played by a different actor in this episode
The vest Myra wears during the dance contest is the same vest Laura wears during the title sequence.
This is the 2nd time that Carl's back goes out during a dance contest. The 1st was in Season 2 ep 4 Flashpants.