Lisa: I haven't seen you in school.
Colin: Just moved from Ireland. My dad's a musician.
Lisa: Is he...
Colin: He's not Bono.
Lisa: I just thought, because you're Irish and you care about...
Colin: He's NOT Bono.
When "Emperor" Moe appears in front of Marge, after she and the kids return, the two cartridge belts swung over Moe's shoulders switch from his left over the right, to his right over the left.
When Homer and Bart jump the gorge, the ambulance that crashed into the tree in "Bart the Daredevil" is still there, crashed in the tree.