Blurred Adobe Flash Player Fullscreen: ATI Catalyst

When I enter full screen mode in Adobe Flash player, both the played video and the GUI become low resolution. This occurs on the old laptop I recently obtained, with different versions of the Flash Player plugin and different browsers, if Hardware Acceleration in Flash is activated. Video playback in media players works fine.

This looks like a limitation of the graphics hardware or drivers. I would like to be able to use what limited acceleration there is. It doesn't do much on this computer or with the slow Flash in general, but shaves about 15% off the CPU usage (on this particular old computer). The computer is barely able to play back 720p with h/w acc.

I located this thread, but no explanation was provided there. The problem is not specific to YouTube and occurs with Daily Motion too.

I've never seen this problem before, and was able to use the Flash plugin on Intel 965G graphics and Celeron 420, which are weaker.

CPU: Intel Celeron M440 "Yonah" at 1800 MHz

Video: ATI RS600M at 1280*800 px.

ATI Catalyst v7.10

8.423-071011a-054910C-Samsung

This is the latest Catalyst that is compatible with older OpenGL games. I tried a few driver versions to find a stable one, but didn't check Flash Player.