Continuity mistake: During the archery constest, in one scene Prince John has a ring on his right paw with no jewel, then all of a sudden the jewel appears. a few scenes later he has three rings on that paw, and later he has no rings at all.
Continuity mistake: When Wilbur is meeting Charlotte's three daughters in the barn entrance, the medal that the farmer hung there keeps appearing and disappearing between shots, though the duration of the scene.
Continuity mistake: As Charlie Brown, Patty, and Marcie are talking, the grandfather clock strikes four. Trouble is the pendulum is stuck in place, first on one side, then the other. It doesn't swing.
Continuity mistake: When Linus and Lucy are talking to Snoopy he's got a shopping cart stuck on his right leg. Then, when he's getting on the bus it's suddenly on his left leg.