Have you checked to see if you have any other scenery files that are causing a conflict? Some culprits may be Dallas DFW Megascenery or some other AFCAD file that is in your "addon scenery" folder. You may also want to move your KDFW to the very top of the list since KDFW is more demanding than any other FSDT scenery. I have my KDFW listed first followed by KLAX, KLAS, KORD, KJFK etc.