External monitor has "snow" at 1080p/i when connected to MacBook Air When I connect an external monitor to my new MacBook Air via Mini DisplayPort to HDMI, I see the extended desktop but there are snow-like artifacts. When I change the resolution to 720p, the screen looks normal.


MacBook: 13" i7 MacBook Air (late 2011)
Monitor: 23" ASUS VH236H LCD
Adapter: non-Apple Mini DisplayPort to HDMI


I have tried other standard resolutions (1024x768 and higher) with the same effect. I have also tried toggling between 50hz and 60hz, 1080i and 1080p, each of which causes the same issue.

I get the feeling it has something to do with my relatively cheap adapter cable, but am unsure. Thoughts?
Likely to be the adaptor cable if it's cheap - might not be able to handle the HD throughput (although outputting to HDMI, you'd think it'd be able to). 

While this sounds counter-intuitive, try moving around the alignment of the second screen as this might ditch the 'snow'. 

Also, have you tried the screen with any other HD inputs?