I dont think this issue is related only to ATI driver ; many with different drivers have posted this issue in the installation/upgrade forum. My Dell inspiron 5160 has the XGI VOLARI XP5 driver and i was hitting the black screen using LiveCD and after upgrading from dapper. After upgrade from dapper, i shifted to trident driverr and added modeline to the xorg.conf. Attaching the initial (bad) xorg files and the modified ones.
** Attachment added: "Volari XP5 black screen issue - xorg files" http://librarian.launchpad.net/4967258/XP5_black_screen.tar.gz -- [edgy][regression][rv280] black screen and console freeze when X starts https://launchpad.net/bugs/67487 -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
