Alright, everything is stable using Line3x and Line5x. It’s interesting that using 4x with my SNES gives me no trouble whatsoever. I would assume that the SNES being the most finicky system would be a good sign for NES compatability. I recognize this is a resolution issue, which means communication with the TV is obviously involved somehow, but I’m not really using a standard resolution for the NES or SNES inputs, so I’m surprised 4x on the NES wouldn’t work. Any ideas?