The Scary Sky Skeleton - S1-E6
Audio problem: During the gang's ride on a bumpy road Fred warns Shaggy, Scooby, and Scrappy about some more bumps coming up. He's interrupted when they hit the bumps, then the word "bumps" comes out of Scooby's mouth.
Scooby-Doo and Scrappy-Doo (1979)
1 audio problem - chronological order
Starring: Don Messick, Casey Kasem, Lennie Weinrib, Heather North
Continuity mistake: When Scooby and Shaggy are at the "Hotus Dogus" stand in the Coliseum, you can see that Scooby has two flags in his left hand, but after a quick close-up of Scooby, we return to him and his flags have disappeared.