I just bought a MBA 2015 a few days ago. I'm still figuring out how to work it, I've used iOS for a while but always used Windows. I had a MBA 11" briefly a couple months ago, and it correctly displayed my monitor (via Thunderbolt to VGA adapter), and I could use the max supported resolutions, 1900x1200 and 1080. That was a 2014 MBA 11.6, and the MBA I just picked up is a 2015 13" and it thinks my monitor is a generic 13.9" when my first one detected it as a 24" correctly. I would think if anything the newer model Macbook would support it better. On Windows it would probably be a driver issue but I have no idea on one of these. Can anyone lend a hand? Thanks