GTX970, HDMI and SteamOS

Hello, I just installed SteamOS using the GTX970 linux driver.

Everything worked fine, but I have one issue that I don’t know how to tackle. Even though the driver work properly using the DVI/VGA connector:
If I switch to using the HDMI port, SteamOS fails to boot. Under Windows7 this doesn’t seem to be a problem. Any hints to how I might handle this would be highly appreciated. I don’t even know how to start debugging this problem.

Kind regards.

plz provide nvidia bug report by running script as root user. Is that mean when you connect display to hdmi port and start X - X is failed to start ?