Created attachment 20965 [details]
Used xorg.cong

Ubuntu 8.10 on lg-s1 laptop, x1600.

I use the radeon driver. The last version working for me is:
1:6.9.0+git20081003.f9826a56-0ubuntu2
Found on the ubuntu main repos.
When trying to upgrade to any later version, beginning with:
1:6.9.0+git20081003.f9826a56-0ubuntu2_1
and upward, the system boots up normally, I get sound and can login - but the screen is blank. I have no signal, and the system is apparently unaware of it.

The changelog between the working and non-working version is:

xserver-xorg-video-ati (1:6.9.0+git20081003.f9826a56-0ubuntu2.1) intrepid-proposed; urgency=low
Add 103_dithering_rework.patch: Complete, correct fix for dithering
    issues we'd initially worked around in patches 101 and 102.  Those
    patches also appear to have introduced regressions on certain hardware,
    which this rework addresses more elegantly.  This patch essentially
    includes all of upstream's work up to commit 435cf7da, except that it
    drops commit 0975e007 (rename radeon_memory to radeon_legacy_memory)
    which is unrelated to the dithering problem.
    (Closes LP: #274234, #284346)

I attach xorg.conf, lspci and logs for working and non-working drivers.