Continuity mistake: After Gromit runs away he starts looking at signs. In one shot, a blue sign goes over the one Gromit is reading (Room to Let), but in the next shot it's not. (00:12:20)
Continuity mistake: When Wallace is put into his overalls he's still wearing his green pullover. A moment later he suddenly doesn't wear it anymore but a complete white shirt. He couldn't have just taken off the pullover as the shirt under it is actually fake (The collar is actually part of the pullover and the arms are just stuck on).
Continuity mistake: After the opening shot of Spunky and Hunky walking, they are shown grazing on some grass. Spunky sucks up a flower and then turns his attention to a dandelion. When he does, it cuts to a close up, and suddenly the dandelion has gotten much bigger, and the surroundings of Spunky change up quite a bit. (00:00:50)
Continuity mistake: After waking up, Lulu's clothes are suspended from the ceiling and she leaps from the bed down into them, getting them perfectly on her in an instant and then runs off. Her hat is not amongst the items, and as she runs off screen you see that she has nothing on her head. But the shot changes to her running directly to the bathroom, and suddenly her little red hat is on her head. (00:01:10)
Continuity mistake: After Lugnut says "Pedal to the metal" and the Champ's mechanic says, "Come on, Cruise, come on", the scene cuts to Cruise and Wrangler on the race course. Wrangler is ahead of Cruise and Cruise is behind Wrangler, to his right. In the next shot, Cruise is suddenly directly behind Wrangler. (00:28:35)
Revealing mistake: When the Level 3 Sentry is firing up into the air for no apparent reason, it fires some rockets with a clear defined smoke trail behind them and disappear off screen. Then the shot jump cuts to further away and suddenly the smoke appears again, but the end of the smoke trails are solid and crisp indicating the animators used the smoke animation as if the rockets had just been fired from that spot... in the middle of the sky. (00:01:10)
Continuity mistake: When the Wolf runs to the cabin, the front door is initially made of wood. But when the Wolf opens all the doors and finds McPoodle waiting for him, the front door now has molding on it.
Continuity mistake: When Goofy searches through the dresser drawers one of the ghosts causes trouble, then Goofy breaks through the top of the dresser and winds up trapped inside, but when all four ghosts appear the dresser top is perfectly fine and that damage has vanished. Also, two of the drawers (one large and one small) fall out of the dresser, but as the four ghosts are pushing the dresser those two drawers have reappeared in their proper places.