Yea, I was thinking it's due to the cable too. However, my research led me to believe otherwise. People on other forums say HDMI transmits digital signals, so it will either work or don't work at all. Oh well, I'm gonna go get a better quality cable tonight just to be sure.
1. Go to CCC and reset everything to Factory Default. If this does not fix the problem, try #2.
2. The monitor must have a VGA cable & your video card should have a DVI->VGA adaptor. Try to connect your monitor via the VGA cable. Do not worry about any loss of quality by going analog. At 1920x1080 VGA is fine. I myself find VGA connection less problematic and smoother than HDMI. And if you connect your PC to your monitor via VGA, you free up the HDMI port for media players/Bluray/DVD if you have them.
By the way, very nice monitor. Hope everything works fine.