Could you try upgrading xserver-xorg-xxx to unstable version to see
whether the problem persists in later versions?
Just tried that, setting source.list to unstable, starting interactive
aptitude, and trying to '+' various xorg-related packages. All
of them seemed to run afoul of
xserver_xorg-code conflicts with xserver-xorg-video (provided by
lots of packages, including the xserver-xorg-video-fbdev 1:0.1.0.5-2
I'm currently using.)
or the like. Telling it to update xserver-xorg-video-fbdev doesn't
help. Telling it to update *every( installed package whose name
contains the text "xerver-xorg" doesn't help either.
By the way, installing a complete sid system a few months ago didn't
help either.