ATI HD4770 with 13.1 legacy driver on KDE 4.10.1 has a number of issues with direct rendering mode on.
It produces artefacts doing several operations, like switching applications to fullscreen or simply launching Steam or XBMC.
Almost every application in fullscreen mode the video ceases to update. Several examples are VLC video freezes after the controls panel closes, XBMC video goes black when playback starts. Games keep running but the image displayed gets stuck on the desktop, same with adobe flash player.
Image displayed flicker when enabling disabling desktop composition and on other occasions.
Gentoo Base System release 2.1 64-bit
These fixes are greatly appreciated, keep up the good work.