Well, I bought this one since my monitor had a DisplayPort and a VGA port. So, the only easy way to connect my MacBook Air 11" to the monitor was to use the Apple Mini DisplayPort to VGA Adapter. It turns out that often the screen becomes blurry and then comes back to normal. By often I mean every couple of minutes. It is very inconvenient when concentrating on something and your full 23" display goes blurry. I tried another monitor which had a DVI port and used the same MacBook Air. It worked fine. So, bottom line is that there is some issue either with the VGA Adapter or with the MacBook itself (though less likely) when using VGA.