Sandy's Rocket / Squeaky Boots - S1-E8
Factual error: Sandy's dome is both airtight and watertight to keep any water out of the dome and any air inside the dome. When the rocket, positioned outside of the dome, begins to launch, smoke is coming inside the dome. This shouldn't be able to happen if the dome is airtight and watertight.
Factual error: In "Wormy," when Wormy's face is viewed as a close-up in butterfly form, the wrong insect is shown. As Wormy is a butterfly, there should have been circular black eyes, long antennae and a proboscis (tongue). Instead, enormous, rainbow-colored, shimmering eyes, sharp mouthparts and horn-like antennae are seen, distinctive to that of a horsefly. Furthermore, butterflies do not make buzzing sounds, which, again, is a characteristic of flies.
A Flea in Her Dome / The Donut of Shame / The Krusty Plate - S5-E11
Factual error: In 'A Flea in Her Dome' Sandy opened up the door for water to fill her dome. The water even replaced the air on the inside which was above the door, which isn't possible because the air would have to go down through the door to escape the dome.
Rise and Shine / Waiting / Sing a Song of Patrick - S5-E1
Factual error: As Patrick's song causes havoc, two airplane pilots deserts the airplane and deploy their parachutes. The issue with this is that the two pilots should have come to a stop relative to the airplane's movement.
Answer: I believe this is the Season 6 episode "Spongicus".