Comment 13 for bug 250931

I have the same problem on Debian Lenny as well.
With fresh compiled radeon drivers :

drivers :
(II) Module radeon: vendor="X.Org Foundation"
compiled for 1.4.2, module version = 6.12.99

board :
ATI Technologies Inc RV280 [Radeon 9200 SE]

The problem didn't occured in etch with default drivers (or was really less
unnoying)
I haven't found other non-java application with the problem yet, so it has
to do with radeon+java

Running with "vesa" xorg driver solves the problem, but it's not a solution.

I'm also a josm user and got the same message as you do.

Note that I've managed to ease my pain a bit with http://www.linuxinsight.com/your-ati-radeon-very-slow-on-xorg-x-server-1.3.html
But I don't feel it really solves the core problem