Why has battery dropped on MB Air 2012 after EFI Firmware Update?

I recently bought a new MacBook Air 2012 (13.3-inch, i5, 4GB RAM, 128GB SSD). Made my move to Mac from Windows 1-2 months ago with this notebook.

I updated this MacBook to OS X 10.8.2 and that went super smooth. My battery timing was increased a bit. Yesterday, I checked for available software updates from the App Store and got several updates for my OS X, including the new EFI Firmware update for 10.8.2 for MacBook Air 2012.

The update was downloaded and installed correctly, but apparently, my battery timing has significantly dropped like crazy. I'm barely getting 4 hours out of this MacBook today. Before installing this EFI Firmware update, I was pulling around 6-7 hours of battery time with heavy usage.

What could have gone wrong? Just yesterday it was fine, but today battery time is really bad. Any one else also having this issue?

Thanks!