Multiple Desktop Resolutions

I'm currently running Windows 8.1 Update with an NVidia 660TI with two DVI monitors at 1920x1200 and a 1080p TV from the HDMI output. I'm having trouble with the 1080p TV in that when I drag an application (Store or Win32) onto the screen, the top and bottom is truncated when I maximise it. For example, if I drag Windows Media Player over to the TV and maximise it, the play, forward and rewind buttons when visible are cut in half at the bottom of the screen.

Does anyone know what I'm doing wrong?

Your TV is likely only showing 1920x1080 so the image is cropped. I believe all devices need to be set to the same max resolution of 1920x1080.