Its not related to ATI at all... on my Dell Inspiron 8100 with a NVIDIA GeForce 2 Go, I have this same exact bug, with both the proprietary nvidia and open source nv driver. Its not card/driver related obviously.
-- Xorg exits when it receives an ACPI button/lid event https://launchpad.net/bugs/61746 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs