ACPI wakeup state lost after reboot

[joefidler]

I like to use my keyboard to wake up the machine after a (S3) suspend to ram. To enable this I use
"cat /proc/acpi/wakeup" to see which devices I have.

For me the keyboard is PS2K device.

I then do:
sudo su
echo PS2K > /proc/acpi/wakeup

to toggle the state of the PS2K device to "enabled".

I then do a "cat /proc/acpi/wakeup" again to confirm. I can then suspend / resume with the keyboard and it all works.
But... the wakeup setting is lost after a re-boot, and PS2K goes back to being disabled.

With Ubuntu the ACPI wakeup stays set after a re-boot so I suspect that this may be a bug or suggestions - am I setting this up the wrong way?

LInux Mint LMDE, Kernel 2.6.32-5 amd64.

Cheers, Joe.