Unwanted Guest: Part One - S5-E1
Continuity mistake: When Kaiba is speaking to Mokuba and Roland in his office, his computer is positioned toward the centre of the desk. Later in the scene, when Mokuba says, "It'll be the biggest thing since Battle City," the computer has moved closer to the edge of the desk. The computer goes back to being in the centre of the desk shortly after, and also changes position from being near the rear side of the desk to being closer to the front side of the desk. (00:06:43 - 00:07:13)