Comment 23 for bug 1010608

I'd like to add, that similar patch as per post #4 fixed the "suspend" button on my laptop.

mate-power-manager sleep-button settings were ignored, laptop always went into sleep
after pressing sleep-button, despite I set 'nothing' in the action.

I fixed this by adding one line to the /usr/share/acpi-support/policy-funcs script:

PMS="gnome-power-manager kpowersave xfce4-power-manager"
        PMS="$PMS guidance-power-manager.py dalston-power-applet"
        PMS="$PMS mate-power-manager"

It seems acpi in Mint 13 (Mate) is not configured with mate-power-manager in mind.

I haven't dug, whether this has been fixed in upstream acpi.