I have exactly the same probelm with a TAGAN 430W psu.
When I connect the line voltage the board starts and switched off.
When I shut down windows vista or go to S3 the red led is blinking for some time, then goes off.
After that the board frequently starts and shuts down after a few seconds by itself for no apparent reason.
I wanted this energy saver board for my sleeping room, it is unusuable now, am very disappointed.
Let me give the answers to my own question: Intel Active Management Technology.
It's not a bug, it's a feature!
I is activated in bios by default and configured to allow remote control in standby and off mode.
In the box there is no explanation how to configure this, not on paper and not on cd.
Here we go:
Enter bios with F2, navigate to Intel ME.
The default password is admin (case sensitive), you have to change that to a strong password before proceding.
Your password has to be 8 to 32 characters long and must have at least
one upper case character, one lower case character, one number, and a special character like !,@,#,$,%,^,&,*.
Important: If you are using a non U.S. keyboard remember that the U.S. keyboard layout is active when in bios!
Then go to IME configuration and change manageable feature from Intel AMT to none.
Hit ESC and exit bios saving changes.
That's it, more info here:
If someone already configured the IME and you can't enter you may reset it by running the maintenance menu after changing the bios configuration jumper.
REMEMBER: The board must be disconnected from linepower while setting this jumper, otherwise it might be damaged.