Apple released an ATI Radio X1900 XT Radeon Firmware Update on Tuesday.
About ATI Radeon X1900 XT Firmware Update
The ATI Radeon X1900 XT with 512MB of dedicated GDDR3 memory provides an ideal solution for motion graphics, animation, digital photography, or 3D design and visualization. It offers two dual-link DVI ports that can simultaneously support two 30-inch Apple Cinema HD Displays for an incredibly large widescreen workspace.
Whats New in this Version
The ATI Radeon X1900 XT Firmware Update will update the firmware on all of the ATI Radeon X1900 XT graphics cards in the Mac Pro. The updater application will be installed in the /Applications/Utilities folder.
Please follow the instructions in the updater application to complete the process.