Continuity mistake: Carter and Cadet Haley enter the Stargate and we see them through the "puddle." When they come out on The Other Side, their positions are reversed.
Beware the Third Wish - S1-E31
Continuity mistake: The Wicked Wisher throws giant exploding coins onto the field TJ is on, as TJ runs towards the WW. The giant coins remain on the field after they explode, yet when TJ reaches the top of the field, there is no sign of the coins, or their remains.
Continuity mistake: Kai is flying his dragonfly space craft towards an enemy ship in the beginning with his wingmen as they sing. Kai's shadow is cast on the wall behind him on his left, but when the camera cuts to a close up of him, his shadow is suddenly on the other side. (00:02:05)