Trying to solve a riddle. Two different, higher end, video cards are showing video effects on half of the display. The rendered video project is fine.

NVidia Quadra FX 3400 and the Matrox Millenium P690. The computers these cards are in are from different manufacturers. One is a Dell. The other is a custom built computer.

The "preview" monitor in both cases is Windows Secondary Display.

Any guesses?

pc