Comment 42 for bug 444449

Ok - I did some tests:
* Using nv driver: CPU problem does not occurs, to bad it's non-bling-bling.
* Using nvidia proprio driver: Problem does occurs.. (I am using 173.14.20 to get correct powermizer behavior aka force-underclocking)

Some notes:
* Xorg eats a full core (99%) - sysprof gives nothing except '???'
* Moving firefox window (when open on reader) gives CPU xorg spikes (WTF? with compiz on ?)

So, playing around, I found out that the following command (obviously only applicable with nvidia...)
$ nvidia-settings -a InitialPixmapPlacement=1
fixes the CPU usage for reader - added to gnome-session and I can enjoy my FF again...

Hope this helps...