Apple released an EFI firmware update (version 2.9) for the mid-2011 MacBook Air last week to address problems the computer could have while waking from sleep, but recently users have started to report on the company’s support forum that the software was failing to install on their machines, and in some cases leaving them with completely non-functional computers, as first noted by MacRumors.

While some users report that their MacBook Airs shut down for several hours only to suddenly spring back to life, others claim that their machines still won’t startup. In other cases, users are finding that the Mac App Store prompts them to re-install the update over and over. So far there aren’t any reports of a successful resolution to the issue, even through AppleCare channels.

If you haven’t already installed the update, it may be best to sit this one out until Apple has fixed whatever problem seems to be plaguing users at the moment.