I have the same problem, running Feisty on my ACPI-equipped ThinkPad X60, and on_ac_power works correctly for me once booted.
However, the problem seems to be that on an ACPI machine on_ac_power checks for /proc/acpi/ac_adapter.
This directory only exists when the ac kernel module is loaded.
That module is loaded by /etc/rc2.d/S10acpid, which runs after /etc/rcS.d/S30checkfs.sh.
So when checkfs.sh calls on_ac_power, the answer it gets is 255, at least on my machine.
Perhaps on_ac_power should modprobe ac?
I have the same problem, running Feisty on my ACPI-equipped ThinkPad X60, and on_ac_power works correctly for me once booted.
However, the problem seems to be that on an ACPI machine on_ac_power checks for /proc/acpi/ ac_adapter.
This directory only exists when the ac kernel module is loaded.
That module is loaded by /etc/rc2. d/S10acpid, which runs after /etc/rcS. d/S30checkfs. sh.
So when checkfs.sh calls on_ac_power, the answer it gets is 255, at least on my machine.
Perhaps on_ac_power should modprobe ac?