This Slip-up was found in the episode from the 2nd season called "Tube Steaks". Doug has just fixed himself a bowl of cereal and walks to the garage to watch some TV. He unlocks the door and walks in, to see the garage door is open. He turn to find his TV is gone. He walks past the coffee table, cereal bowl in hand, and stands where the TV used to be. He yells, "CARRIE!!" and walks very quickly past the coffee table again still holding the cereal bowl. A different camera angle then shows Doug walking out the door with no cereal bowl. It magically appeared on the coffee table he walked so quickly by, holding the bowl. I guess his bowl is magic!