Hi Kyle,
I have found the culprit to the landing lights issue. It seems that REX has installed certain textures that effect the intensity of the landing lights on teh NGX and 777.
Solution: In the REX 4 Window, go to Textures > Sun\Lighting > Landing Lights. In the drop down menu, I chose Landing Light Textures: For use with RealAir Turbine Duke. (You don't have to own the Duke, it's a built in option via REX software). Hit Install and lights should work normally.
Just thought I'd let you know in case anyone else is having this issue.
Cheers,
Sante-