Originally, this episode was going to have a song with Patty and Selma called "We Love to Smoke," but it was cut for time. The song is available on the season eight DVD set and on the Simpsons: Yellow Zone album.
The failed skit that Krusty attempted to do in his Krusty Komedy Klassics, "Mad About Shoe," was a reference to the sitcom Mad About You. He also mentioned a "NYPD Shoe" skit when he learned that the audience didn't like it and warned that it was the same thing, a reference to the show NYPD Blue.
Homer doesn't recognize Kearney as the punk kid who threatened to egg his house if he didn't give him candy (as seen in season three's "Treehouse of Horror II") or one of the kids he was going to buy beer for (as seen in "The Springfield Connection").
Krusty's show is called Krusty Komedy Klassics, yet Krusty performs new material.
The tree Grampa crashed into at the end of the episode isn't usually in the Simpsons front yard.
In the deleted song, "We Love to Smoke," Patty and Selma claim that they'll be dead before 2003 from all the smoking they've done, but they're still alive as of 2013 (though a future episode will have yet another Simpsons character die, and the only clue is that the voice actor is an Emmy winner. Since Julie Kavner voices Patty and Selma, it wouldn't be out of place to assume that they will die).
When Shary Bobbins gets drunk in the living room, she has on a blue dress. When the family comes over to comfort her, she's in her black dress she wore when she first arrived.
According to the audio commentary, when Marge, Lisa and Bart sang this part: "But we're happy just the way we are", Homer Simpson was not singing. That's because Al Jean and Mike Reiss forgot to record Homer Simpson. "The show must go on." - David Silverman, Supervising Director.