On Monday, 9/6, they aired "Comedians" and "Carwash". Then, today (9/7), they aired "Couch-fishing" and "Comedians". However, the Comedians part tonight was different. Between the Vince Neil song "Sister of Pain" and Belly's "Feed the Tree", they inserted something on Tuesday.
My only guess as to why this happened is that they needed some extra ad time on Monday, and made another version. Of course, this could be WAY off base. Anybody got any other ideas?
I just noticed that the juggling sequence was also longer in Tuesday's episode. This is where Beavis lights the papers, and presumably leads to the Laff House burning.