Yes, very strange. I am going to rule out power aside form a specific voltage wit the pci-e bus. I have a 1 Kw PSU and am not over drawing it.
So here are my thought from scouring the internet:
1) The pci-e bus is utilizing the incorrect voltage for that card causing it to loop the motherboard and make it reboot on a shutdown command
2) The motherboard has a flaw in the BIOS causing the pci-e card to incorrectly send a WOL command to reboot on shutdown
3) Windows 7 is utilizing a flawed driver that incorrectly interperts the wifi card to present a WOL reboot command or startup command during normal shutdown.
What I am able to do is kill power to the PSU and the restore power. I then can power up the system via the "power button" and hold it for the bios setting of 4 seconds to shut off the system.
Reason I am going to rule out the motherboard or power is this:
- The DWA-552 PCI card does not suffer from this issue
The driver for both the 552 and 556 are at the very least the latest vista driver (I do not have the revision number right now)
This only happens when issuing a shutdown command from within windows or pressing the power button when Windows is running.
Things still to do:
Test this in another system running Vista to rule out the card.
I will post my findings.