Beyond the Farthest Star - S1-E1
Other mistake: When showing Scotty on the bridge, some of the frames show more of his body than others. In those frames, you can see that he lacks legs.
Other mistake: When Scooby is eating the hot dogs at the "Hotus Dogus" stand, his tail goes transparent.
Inspector Kenmochi the Murderer File 1 - S1-E19
Other mistake: There's a coloring mistake in the glass in front of Busujima in the shot when finishes playing his handheld game and sends the waitress away; the glass is half empty / half full...but vertically. The part to the right of the straw is full to the brim and the part to its left is nearly empty. (00:10:35)
Other mistake: In the episode where Tino is freaking out about the "FunVille" Arcade door looking like the mouth and face of a clown, it does. But in another episode I saw this morning (where Carver pretends to be all tough) the FunVille door is like any other normal door.
Other mistake: It is established that Drs. Quest and Hartman speak the Po-Ho's language, but when they are captured, Dr. Hartman is translating to Dr. Quest how the Po-Hos are going to torture them.