X11 display terribly slow after upgrade

[Zlatko Calusic <zlatko.calusic@iskon.hr>]

Hello!

First post to the list after a looong time, so be gentle. :)

I'm using lenny/sid distribution. Few days ago, after Xorg packages
got upgraded to 1.3.0, display became very slow. Every redrawing,
every scroll, it's all slow. On one machine it's actually unusable
(Radeon Xpress 200M), on this one (Radeon 9500 Pro) it's just very
slugish and annoying, feels like I'm running on P166 (instead of
E6600).

Is this a known bug? I'm quite surprised only I've noticed this (I
went through the list archives). Also, it's quite hard to report this
as a bug, because X11 is composed of so many packages, I don't know
where to start. :(

Help!
-- 
Zlatko