I have had a problem with a flaky HDMI port on the card for a few months now. If I shut down the computer and switch cables between the two Philips monitors connected each of the HDMI ports, the problem goes away. Today, no luck. The problem port is the right one when looking at the back of the computer. The driver is up to date. Win 7 64 bit machine, HP Z400. Is this a hardware problem?