Catalyst 8.12 from ATI hotfix

[Simond]

ATI has made available for download a hotfix version of its Catalyst driver 8.12, to be used in combination with video cards ATI Radeon HD 4850 in CrossfireX configuration.

The problem solved by these drivers on a black screen that can occur in the system using two ATI Radeon HD 4850 in CrossfireX configuration. This incompatibility concerns only configurations based on Windows Vista 32bit or 64bit. Furthermore, we note provided by ATI to explain the problem.
ATI Radeon ™ HD 4850 series: Installation of Catalyst 8.12 results in a black screen preventing Windows Vista from loading.

Symptoms:

After installing ATI Catalyst driver release 8.12 for two or more ATI Radeon HD ™ 4850 graphics cards in a system with ATI CrossFireX™ technology, the system restarts and halts on a black screen. After installing ATI Catalyst driver release 8.12 for two or more ATI Radeon ™ HD 4850 graphics cards in a system with ATI CrossFireX ™ technology, the system restarts and halts on a black screen. The black screen occurs prior to the loading of the desktop for the Windows Vista 64-bit or Windows Vista 32-bit operating systems. The black screen occurs prior to the loading of the desktop for the Windows Vista 64-bit or Windows Vista 32-bit operating systems.

This issue only occurs when two or more ATI Radeon HD 4850 graphic cards are installed in the system with ATI CrossFireX technology. One single ATI Radeon HD 4850 card will not encounter this issue. One single ATI Radeon HD 4850 card will not encounter this issue.

Applicable Products
The issue applies to the following products

Drivers
ATI Catalyst 8.12 release

Graphics Cards
2 or more installed ATI Radeon ™ HD 4850 series graphic cards in a system with ATI CrossFireX technology

Operating systems
Windows Vista 32-Bit Edition
Windows Vista 64-Bit Edition

Further information, along with links for direct download drivers, are available on ATI's web site