Apple has issued a new EFI firmware update for the MacBook Air, v2.7. The patch
is aimed explicitly at 2013-model Airs, and copes with a bug that caused black screens to appear when trying to install Windows 7 or 8 using Boot Camp Assistant. The problem was triggered if both an external optical drive and a USB stick were connected at the same time. Simultaneously, Apple has tweaked the firmware to ensure a Mac will boot into OS X by default after Windows 8 is installed.
The update is the second directed at the Air in less than a month. An October 1st SMC update
fixed an issue that caused some systems to suddenly freeze or shut down if they exceeded over 1,000 charge cycles.