If there's no digital signal being sent to the port, it won't be active. So if the computer shuts down and the HDMI signal stops, the monitor would usually go to standby and the port wouldn't be available.
If you can see the POST screen (boot screen), but then nothing happens after that, it's a Win7 driver issue. Have you updated your drivers to the latest version from GForce's website?
i have this problem too.....i discovered that when i shut down my computer in my monitors source menu , Samsung p2470hd, hdmi is greyed out and it shows no signal beacuse it remotes itself in the PC mode(analog VGA) . U can select HDMI PC in the source menu when u open ur pc and u can see the image when WIn 7 logs on, still i cant see an image when it boots. My question is....is there any way for the HDMI PC in the source menu to stay active while computer shuts down or is in stand by????
Samsung monitor + Gforce 8300....i surely believe it is a monitor problem!