[RKDinOKC]

If I remember correctly the Macbook Air only has a USB port and a Power port so there is no way to even plug in a external display.

My Macbook Pro has 2 video cards built into the motherboard. One really fast one with higher resolution and a slower lower res one. It uses the slow card to save battery if on battery power, no external display, and are not running software that needs cranked up video. An external monitor defaults to the faster card because if you have an external monitor you are most likely running off AC power.

On my first Mac, it was a Mac 512 with built in grayscale monitor. In 1987 I had an external grayscale full page display that used the SCSI port. Was able to use the mac's display AND the external monitor at the same time. In fact, the Macintosh OS was capable of running multiple video cards and monitors at the same time LONG before Windows and the PC platform supported it.

In 1991 I did industrial videos and animation on a Mac Desktop Tower. It had 3 video cards and an Video card specifically for both input and output to TV and/or Video recorders. It was nice to have the screen space of 3 monitors and a TV to work with the video, video editing controls, animation and animation programming windows all at the same time.

In 1996 my HOME computer was a Mac Performa VEE. The VEE stood for Video Editing Edition. It was a mini tower that came from Apple with a video card for a monitor AND a video card for digitizing and outputting S Video it also had video editing software. This was when S Video was a good as it got.

So yeah, it's most likely the Apple component of your setup causing the problems.