Monzo, you've resurrected a post from August, there have been several hotfix release since then.

Here's what fixed the freezes for me. 1) Turned of FSUIPC autosave function.2) Turned off antivirus software - in particular, all real-time screening. Putting FSX in the "don't scan" list did NOT help. I had to completely turn off real-time scanning.3) Turned off autogen and traffic.4) Lowered sliders from "ultra high" to "high" or "medium high", This was with Paul's help (from PMDG). Haven't had a freeze since. I did not install hotfix 4: I don't even know where to find it. Oh, Traffic X works OK, it's just the internal FSX traffic that seems to be a problem. Would I like to be able to run with full sliders? Of course. I'm reasonably sure that in the fullness of time whatever this glitch is, will be fixed. Heck, I still have disappearing panels in the MD-11 on resuming a flight, and the autopilot in the 747X still goes wonky occasionally. Less than 1% of 737NGX users are having the freeze problems. It looks like certain combinations of FSX, 737NGX, and high memory usage cause the freeze. Once FSX memory usage goes over 1.2 GB (as reported by Task Manager; ATI MemoryViewer reports 1.6 GB and SysInternals Process Explorer 1.8 GB. One trick I've found to get around the land-and-freeze/OOM/CTD problem is, before landing, turn the scenery sliders to "medium high". and keep traffic to 20% (FSX) or 50% (Traffic X). Now if I could only figure out why the installation of a ATI Radeon HD 6970 card completely removes sound from my computer. The on-board sound, dead. A add-in sound card, ditto. Can't test the HDMI sound out, don't have a HDMI TV or monitor. I've removed and installed devices & drivers, tried different versions, all no go. On the other hand, wow that is a nice graphics card! Dan "lensman" DavisonAsus P6T, [email protected], 6 GB DDR3-1600, Radeon 6970 2GB GDDR5, 1x60GB SSD, 2x 1TB WD HD, 1X160GB HD, Antec 900 case, 7 fans, XFX 850 watt PSU; Saitek X52 HOTAS; Win XP Pro SP3, FSX+Acceleration, TrafficX, all PMDG a/c, LDS767, Radar Contact, FS2Crew, DodoSim 206; 2 junky monitors

Thank you for the information. I had some time over last weekend to try out different things including some inserts/updates to the fsx.cfg which I found in AVSIM (from *******). I noticed now that there are less freeze-ups now, When the freeze-up does occur, I can browse the web for about 5-6 minutes and then FSX/PMDG 737NGX will resume from where it froze which is better than scrapping the flight and starting over. BTW: PMDG 737NGX is a MASTERPIECE! -- really, a wonderful product which works great with REX and I am looking forward to flying with TRACK IR. Regards,Monzo Processor(Intel® Core™ i7-2600K Processor (4x 3.40GHz/8MB L3 Cache)) Processor Cooling(Liquid CPU Cooling System [sOCKET-1155] - [Free Upgrade] Standard 120mm Fan) Memory(16 GB [4 GB X4] DDR3-1600 Memory Module - Corsair or Major Brand) Video Card(NVIDIA GeForce GTX 580 - 1.5GB - EVGA Superclocked - Core: 797MHz - Single Card) Video Card Brand(Major Brand Powered by AMD or NVIDIA) Motherboard(ASUS P8P67 LE) Power Supply(750 Watt -- Thermaltake TR2 TRX-750M - FREE Upgrade to Thermaltake 850 Watt) Primary Hard Drive(1 TB HARD DRIVE -- 32M Cache, 7200 RPM, 6.0Gb/s - Single Drive) Sound Card(3D Premium Surround Sound Onboard) Network Card(Onboard LAN Network (Gb or 10/100)) Operating System(Microsoft Windows 7 Professional + Office Starter 2010 (Includes basic versions of Word and Excel) - 64-bit) Speaker System(Logitech Z506 5.1 Surround 3D Sound Speakers + Subwoofer - Black) Wireless Network Adapter(LINKSYS AE1000 802.11n Dual-Band Wireless USB Adapter) USB Cables / Accessories([Hub] USB 3.0 External Hub (4 X Ports))

This just happened to me for the first time last night, flight from KDEN to KPHX, about 20NM from the airport, I changed the arrival RWY as the winds had changed and nothing in the panel worked, could not disengage the AP, nothing, the plane kept flying on it's final course and maintained elevation, but nothing worked, joystick was also useless, FSX did not crash, plane just kept going on it's own.... :(

Open a ticket with PMDG.

Oops, wrong thread.