Using the attached xorg.conf, which sets up 2 Xorg screens, when I run any OpenGL program (tested with glxgears, OpenArena and mplayer), the screen is frozen while I am not moving the mouse or typing something in the keyboard. So, if I run mplayer with gl backend, the movie (including the audio), plays nicely while I am moving the mouse, and freezes while there is no input. When an OpenGL application is started, every moving/flashing thing in both screens is affected, so if I run glxgears on DISPLAY=:0.1, the network usage icon in the taskbar of DISPLAY=:0.0 also freezes while there is no input. If I run one OpenGL application in one screen, and another in the other screen, the effect is avoided for a few seconds. If I comment everything in the xorg.conf related to dual-screen zaphod mode, I get an extended desktop and the bug is not hit, so OpenGL applications works as expected in both monitors.
Created attachment 39656 [details] The configuration file.
*** This bug has been marked as a duplicate of bug 29726 ***
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