When kdetv starts I get black screen - helps for that only resolution change. Then the video is displayed without problems to the time when I move/resize some windows (kdetv or others) - the overlay video flashes (looks like video window is redrawn all the time) and sometimes goes black, too. It flashes more when some window is on top of the overlay video (kdetv) or even animated mouse cursor on top of overlay window (for example when running an other application). When I move overlay window the overlay video is moving after the window (not accurate in window).
It doesn't happen without overlay or with opensource radeon driver.
Yesterday I've noticed that xrandr setting modes stopped working for me - everything looks ok from the xrandr command line (even verbose is saying that it's setting mode) but video resolution doesn't change. I've used it in bash script with kdetv to get rid of this black screen when running kdetv without need to use ctrl + alt + "+"/"-". This key combination works fine with resolution change and before yesterday/maybe day before xrandr worked fine.