XPS15 L521X - Connecting to 2 External Monitor Resolution Issues

I'm connecting 2 monitors to my XPS 15:

1) HP 2311x via HDMI port

2) LG 19 M37D via DVI-D port with j5 create Mini Display Port Adapter (JDA132)

I'm getting the high resolution with the HDMI port but having issues with the Mini Display Port.  When I go to change the screen resolution for the LG monitor I get the message "Your resolution is lower than 1200X900.  Some items might not fit on your screen."  The native resolution of the LG monitor is 1366x768. 

Any suggestions on how to get the LG Monitor to display at native resolution?

Thanks!

John