Apple has released MacBook Air EFI Firmware Update 2.9 for MacBook Air models released in mid-2011. Ostensibly, the update addresses two issues related to waking from sleep — a bug that prevented waking in a timely maner and a problem that caused fans to run at full speed after waking. However, there are multiple reports on a discussion thread at Apple Support Communities that installation of the firmware update is causing some MacBook Air laptops to shut down completely and not start up again for a lengthy amount of time (so much for that timely waking fix). Additionally, other users report still seeing the EFI update in the Mac App Store’s Update section even after applying the firmware multiple times. This might be one to wait on for a few days to see if Apple reissues EFI Firmware Update 2.9. (Free, 4.1 MB, 10.9.2+)
Extract Directly from Time Machine
Normally you use Time Machine to restore lost data in a file like this: within the Time Machine interface, you go back to the time the file was not yet messed up, and you restore it to replace the file you have now.
You can also elect to keep both, but the restored file takes the name and place of the current one. So, if you have made changes since the backup took place that you would like to keep, they are lost, or you have to mess around a bit to merge changes, rename files, and trash the unwanted one.
As an alternative, you can browse the Time Machine backup volume directly in the Finder like any normal disk, navigate through the chronological backup hierarchy, and find the file which contains the lost content.
Once you've found it, you can open it and the current version of the file side-by-side, and copy information from Time Machine's version of the file into the current one, without losing any content you put in it since the backup was made.
MacBook Air EFI Firmware Update 2.9
Set up short abbreviations which expand to larger bits of text,
such as “Tx” for “TextExpander”. With the new custom keyboard,
you can expand abbreviations in any app, including Safari and
Giving me a nice warm and fuzzy apple feelling!
All is well after a full shutdown and restart but there is/was no FW update :-(
I didn't really need that near heart attack.