I am experiencing a similar problem on a Vaio Z1 with Radeon Mobility M6 LY running Dapper. There are regular complete freezes, reboot necessary. Disabling DRI does not help. The problem disappears when switching from "ati" (or "radeon") to "vesa" in xorg.conf. Using "ati" (or "radeon") certain buttons under gnome are not displayed correctly, there is like a grid of wrong pixels. This indicates already that there is a problem. Also this effect disappears when using "vesa" instead.
-- X / Gnome freezes randomly https://launchpad.net/bugs/49395 -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
