I think, it's because eeepc-config and hotkey-setup (?) react to this key both. For me I comment in /etc/default/eeepc-config lines:
EEEPC_HOTKEY_MUTE_TOGGLE="acpi_fakekey $KEY_MUTE" EEEPC_HOTKEY_VOLUME_DOWN="acpi_fakekey $KEY_VOLUMEDOWN" EEEPC_HOTKEY_VOLUME_UP="acpi_fakekey $KEY_VOLUMEUP"
I think, it's because eeepc-config and hotkey-setup (?) react to this key both. eeepc-config lines:
For me I comment in /etc/default/
EEEPC_HOTKEY_ MUTE_TOGGLE= "acpi_fakekey $KEY_MUTE" VOLUME_ DOWN="acpi_ fakekey $KEY_VOLUMEDOWN" VOLUME_ UP="acpi_ fakekey $KEY_VOLUMEUP"
EEEPC_HOTKEY_
EEEPC_HOTKEY_