Comment 1 for bug 372789

That's not a notify-osd specific bug, but a compiz-related issue. For example you can trigger the same kind of flashing by simply starting totem playing back some video, switching totem to fullscreen-mode and then in fullscreen-mode move the mouse (to that the on-screen UI-elements appear). That causes the exact same kind of flashing.

From my own investigation on the issue:

- on nvidia-GPU (with proprietary driver), on i965-GPU (with kernel 2.6.30, xf86-video-intel 2.7.99.1, using UXA)
- using compiz (e.g. Visal Effects level set to "Normal" or "Extra")
- unredirect fullscreen window enabled (default setting in Ubuntu 9.04)
- flashing/flickering occurs on fullscreen windows if smaller window appear on top of them
 - example apps tested: fullscreen totem, fullscreen inkscape, fullscreen screensaver

temp. fix:
- disable "unredirect fullscreen window" in compiz
- or don't use compiz but metacity+compositor
- or just use plain metacity

This fix I regard as temporary for the moment as not all xorg video-drivers allow "redirected direct rendering" (in layman-terms: OpenGL in a composited environment). For systems-setup though with working DRI2 (e.g. i965 GPU with UXA on kernel 2.6.30 and xf86-video-intel 2.7.x) or systems with nvidia-GPU with proprietary driver "unredirect fullscreen windows" can savely be disabled, thus eliminating the flickering/flashing completely.

Once all OpenSouce xorg video-drivers support DRI2 "unredirect fullscreen windows" can be disabled by default again. Note: "redirect fullscreen windows" is a workaround in compiz to cater for the fact that DRI2 isn't common place yet. So this is nothing to fix in compiz. xorg video-drivers just need to pick up DRI2. If a user has a nvidia-GPU running the proprietary driver "unredirect fullscreen windows" can be disabled right away.