I've tried to enable the mail led on my Aspire 5673; I loaded acer_acpi with "force_series=2490", so the acer-wmi::mail appeared under /sys/class/leds, but doing echo 1 > /sys/class/leds/acer-wmi::mail/brightness changes nothing... the led remains off.

Is there a way to enable it? I noticed that you already have DSDT dump for 5670... I will be happy to send you every memory dump you need, just tell me.

I run ArchLinux on kernel 3.0