3D windows hang temporarily on focus change
I am seeing issues where OpenGL (and wine-boxed d3d) locks up temporarily (no redraw is being done) on window manager focus switches; no game logic runs if the game is singlethreaded (obviously).
Creating a tool widget somewhere and tearing it down again (with the implied focus switch) is sufficient to un-lock the 3D renderer - e.g., just opening a right-click popup somewhere and closing it again works fine.
However, it is extremely annoying, as the reverse is also a problem: Any game played stops as soon as any OSD (for example, amarok currently playing) pops up, and resumes as soon as the popup disappears.
I cannot reproduce this behaviour with glxgears; however, with Neverwinter Nights (the only game I play frequently) it happens all the time, as does it with wine-started D3D games.
I have observed this behaviour on all kernels since 2.6.18 (though it did not necessarily start with that version), and on all NVIDIA driver releases I care to throw an axe at.
I am running a quad-head xinerama setup with two 7900GT driving the screens, on openbox (though the issues are with kwin too) - also, find the bug-report attached below.
How can I help to fix this?