I have two systems with ATI graphics running Cauldron
My workstation is working great with cauldron
One of them, an half old Thinkpad T60 was working great until I updated it july 6, after having had it without updates for maybe a week.
( That is my wife's production machine...!! )
With both proprietary as well as xorg ati drivers, the display change to just vertical lines at login screen, and also at desktop.
As a workaround it now use xorg vesa which works but is of course slow and have other issues as well.
Bug 18883 - ATI graphics broke after an update first days in july