Other mistake: When Tina is writing in her diary and we hear the voice-over she says "So, it's a really great bang for your buck-ing bronco" but when we see the diary it reads "So it's really bang for your buck-ing bronco."
Continuity mistake: Part of the plot of the episode is the port-a-potties being in front of Bob's restaurant. But on the day of the parade, there's a shot of The Land Ship going down the street and there are no port-a-potties in front of the restaurant. When Jimmy comes over to make fun of Bob, they're back in front of the restaurant.
Answer: S04e15, "The Kids Rob a Train."
Bishop73