Just a few days after the release of the HD 4850, DAAMIT has issued a hotfix for the HD 4800 series.
The new hotfix should improve overall stability and performance, thus pushing the HD 4850 even closer to the green team competition. The hotfix also comes with the Display Driver and Catalyst Control Center. We learned that it should improve and fix many troubles related to Crossfire that some people have experienced.
According to some of the rumors, this one also brings some extra performance to the HD 3870 Crossfire as well, but that isn't confirmed and might be an isolated case. We will make sure to try to find out.
You can find the hotfix here.