Corrected entry: When Homer gets stuck in the water slide, a few kids are sent down to dislodge him, and they get stuck too. However, when the section of pipe containing him is removed later, the kids are nowhere to be seen.
Corrected entry: Marge should not have received the letter from Ringo Starr because of the fact that she was in her teens when she wrote the letter to him, and she was not living in the Simpson family's current house.
Correction: I'm assuming Springfield has a postal service, and all postal services have the change of address forms she could have (and probably did) fill out when she moved.
Correction: They were able to pull the kids back up the slide, since they weren't wedged in the pipe like Homer was.