Apple has released Mac Pro EFI Firmware Update 1.3 . The software is available for download through the Software Update system preference and directly from Apple's Web site.
The software is intended specifically for Mac Pros manufactured in early 2008. It updates the Extensible Firmware Interface (EFI) code installed on these systems. Once the firmware has been updated, the Mac Pro's BootROM version should be MP31.006C.B05, according to Apple.
Apple said the update "fixes several issues to improve the stability" of Mac Pro (Early 2008) models.
It is intended specifically for 2008 Mac Pro models. Users of older Mac Pro systems should not apply this update.