In S-Shivering S-Smurfs, While tracker is out searching for the Smurf Root Papa smurf tells the other smurfs "That is the last of the fire wood", you can clearly see in the background a full log basket.
Sloppy Smurf has four toes on his bare foot, but after he pour's his garbage into the fire and the smoke clears, you can only see 3 toes.