2011 MacBook Air - Installed 10.8, Can't Go Back To 10.7

I upgraded a 2011 MacBook Air to Mountain Lion, however, it isn't playing nice with some enterprise things, so I want to put Lion back on it again.

Booting the Air with a USB stick containing the Lion installer doesn't work (see photo below). I booted it off a USB stick containing the Mountain Lion installer instead, and loaded Disk Utility to wipe the hard drive, because I thought it would refuse to boot the USB stick containing 10.7 if it saw 10.8 was installed.

Anyway, that didn't help, because I still can't it to boot from my Lion USB installer.

When I hold alt and select the Lion installer, I get this screen for about 10 secs before the machine shuts down. I've re-made the Lion USB stick, and I'm using the same USB stick that I used to make the Mountain Lion installer.

Any ideas?

Found out it is because the Lion image I have is older than the MacBook Air, so doesn't have the boot drivers needed.

I'm re-downloading Lion from the App Store.