During the Snow Chase Scene, a cannonball can be seen being shot through the front end and exiting through the back corner of Dr. Scratchensniff's buggy. However, Baron von Plotz and Ralph's buggy are chasing them from behind shooting cannons at them, making it impossible for the cannonball to enter the Dr.'s buggy from the front end.
The hole Wakko makes falling through the bridge is gone by the time the Warners leave the bridge, and for all subsequent characters' crossings.
In the first scenes of the Hungarian Rhapsody sequence, the townspeople are all in their pajamas. However, as the Warners start to leave for the star, they're all in their normal clothes.
At one point during the Hungarian Rhapsody song Rita who is a cat is drawn with buck teeth like a squirrel.