Ok, I plugged in a d-sub15 cable and it works at 1440x900... Maybe there is something wrong with the HDMI output on the card
My JVC LCOS TV was 1080 but would not display 1080 from the computer input. Just got a blank screen. Second output worked fine on another computer monitor. TV manual stated that through that input TV only supported 800 lines. Video card was not the problem, TV was. Reset that second output to a lower resolution and try again.
Check your TV owners manual, you may have run into the same issue that I had.
Hope this helps.