[RP] after toggling display of the message bar, for 10 seconds whole CPU is eaten

[Miernik]

I noticed that after doing anything which toggles the display of the
message bar, for example 'Ctrl-t w' or 'Ctrl-t ?', both when displaying
the message bar, and toggling again to vanish it, for about 10 seconds,
almost 100% of CPU is eaten by the process Xorg (I see that in top, idle
is 0.0%, Xorg eats everything which is not eaten by other processes).
In fact now it eats all CPU for 25, not 10 seconds like it did a few
days ago. Maybe it increases with the ammount of time the X server is
running?

Also when any new window is opened, like starting an xterm, or when any
application opens a new window, also then for about ten seconds full CPU
is eaten by process Xorg.

I use everything latest Debian unstable official packages.
My CPU is Celeron 466 MHz. Both the Xserver and X applications run on
the same machine. I have two monitors and use Xinerama.

Is anybody else seeing that bug? What might the cause be? Anything that
I might test?

-- 
Miernik
http://miernik.name/