I have a 24" ViewSonic VX2453 monitor that supports 1920x1080p, connected using HDMI. However at that resolution, the desktop goes off the screen. Using the Nvidia control panel, I have to set it to a custom resolution of 1804x1014 to display correctly.
The monitor has its drivers properly installed (the correct model name shows up in control panel after installing the drivers), and I'm running 64 bit Win7 Ultimate. I have a GeForce 560 Ti card, if that helps. Why does this happen?