2142 dosnt support that resolution by default, same problem with my 1440x900 widescreen monitor...you have to put a line in your shortcut
right click on your bf2142 shortcut, properties, in the TARGET block...change to this
"C:\Program Files\Electronic Arts\Battlefield 2142\BF2142.exe" +menu 1 +fullscreen 1 +szx 1680 +szy 1050
if you go into video settings, IGNORE THE RESOLUTION IT SAYS..as long as it says a default resolution...the shortcut will override
patch 1.25 is the current update