Amazing, after upgrading to openSUSE 12.1 I’m not able to play Youtube videos. I have ATI Mobility Radeon HD3450 with proprietary drivers installed and have never had such issue in 11.4
Spent really much time while searching for solution
Found this thread about boot splash screen (http://forums.opensuse.org/english/get-technical-help-here/multimedia/467622-full-screen-flash-extremely-slow-intel-i-fixed-sheer-luck-2.html) and this nvidia thread (http://forums.opensuse.org/english/get-technical-help-here/multimedia/468151-flash-hardware-acceleration-opensuse-12-1-a.html) with misleading link Adobe Forums: FP11 Linux Hardware Acceleration? saying that there is no hardware acceleration in Linux. I was shocked! So how did I watch You tube in 11.4 than?
Solution: If you are using AMD proprietary drivers - disable desktop OpenGL effects
Go to System Settings -> Desktop Effects -> Advanced and set Compositing type to “XRender”:
Hope this helps AMD Mobility users