It looks like it's working now on my test bench but I'm really confused. From Dell Dimension 4550 user manual it says:
The options are S1 or S3.
AC Power Recovery
Determines what happens when AC power is restored to the computer.
* Off (default) — The computer remains off when AC power is restored.
* On — The computer starts when AC power is restored.
* Last — The computer returns to the AC power state existing at the time
that AC power was lost.
So I should be setting S3 and Off for the above two settings, but I changed it to S3 and On and now it's actually turning on or resume my PC and hibernating when I switch off IGN.
What's going on???