I can also confirm the bug on a acer Extensa 4101 with Kernel 2.6.20-9. There is no way to poweroff, but restart and suspend-to-RAM support is available without any problems. In Edgy (2.6.17) it works still fine.
That is a dmesg exerpt from these lines which looks strange imho. [ 18.471426] PnPBIOS: Disabled by ACPI PNP [ 19.088000] ibm_acpi: ec object not found [ 25.636000] apm: BIOS not found. Additional I recognize that this bug only appears if you connect to ac/dc power supply. If you shutdown on battery supply it works correctly. Could anyone confirm this? Is there a changelog for apmd, laptop-detect or laptop-mode-tools to 2.6.20 available? thx Thomas ** Attachment added: "kernel-dmesg" http://librarian.launchpad.net/6610118/kernel-dmesg.txt -- rebooting instead of shutting down https://launchpad.net/bugs/71040 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
