Apple has released a Mac Pro EFI Firmware Update in your Mac OS X Software Update. The update is described:
This EFI Firmware Update fixes several Boot Camp and start up issues on Mac Pro computers. If the firmware update doesn't run automatically, open it manually in the /Applications/Utilities folder.
Also available is a Mac Pro SMC Firmware update:
The SMC Firmware Update adjusts fan behavior in the Mac Pro. After this update has completed successfully, your SMC Version will be: 1.7f8. The updater application will be installed in the /Applications/Utilities folder and will launch automatically after restart.