I have been having this issue on select GameCube games that seem to stretch out to full screen, even though I set it to 4:3. Even though I turned on the full screen hack it stretches it even further! I tested this with Custom Robo as shown in the picture and it was overly stretched, with the full screen hack and the glitch on top of it. Does anyone know about what settings I would look change in Retroarch to correct this?