The Crab with the Golden Claws: Part 1 - S1-E1
Audio problem: As Snowy chews through the ropes keeping Tintin tied up, Tintin removes them and then says to Snowy "We've got to find a way off this ship. We've stumbled into a real hornet's nest, here." Snowy then replies with a bark, but his mouth is completely sealed shut and there is a rope in his mouth. For Snowy's bark to be possible, his mouth would had to have been open. (00:13:15)