Hi there, First of all many thanks to the whole PMDG team for the fantastic materialization of the 737NG into FSX.Its pure fun to fly and its depth exceeds my expectations by far with much more to come.However I struggle with a serious problem which occurs frequently and I cannot resolve it by myself so far. I am taking a short trip from KPDX to KSEA with the Southwest 737NGX-800WL. All preperations on the groundand takeoff always work fine without any problems. But after few minutes in the air I frequently encounter a CTD.I have the feeling that it happens when dealing with the autopilot knobs. Last time it happened whentrying to set VS rate for a decent. Suddently everything stopped and after few seconds...the uglyfsx.exe application crash screen. The details or the app crash are related to : - g3d.dll- LCID 1031 I have the following environment : Win7-64, 16GB RAM, i7-2600k, 4.7Ghz, Nvidia 560Ti, using FPS limiter, fresh install FSX+SP2+XP, REX2, FTX NA: CRM/NRM/PNW Anyone out there who has an idea what could be wrong and how to resolve it ?Followed the hints in the NGX introduction guide but it did not help. Also reinstalled the NGX liveries with the current ones.I am running out of ideas...Beside this it runs like a dream. Thanks for your help! Cheers,Jaro