First off, brilliant model PMDG thank you very much to all contributors!! So far I have been able to land manually with ILS dialed in on more than one occasion, but whenever I try to land using Auto-Pilot and align with the ILS the application freezes with the dreaded circling arrow - then inevitably, CTD. I thought at first it was my FSX.configuration. So I mucked around with USEPOOLS = 1 or USEPOOLS = 0 and set the frame rates from fixed at 25 FPS to unlimited. Initially this looked good and I experienced fluid movement, but the moment I intercepted the LOC I noticed the average frame rates dropped from around 30 to around 14 , then when on final before it was necessary to engage the APP button, it dropped to 9, then ... freeze.I have tabbed out Bufferpools from the config and tried without, but this makes no difference to the eventual outcome. I have tried this approach from the North 3 times and each time it captures the LOC then eventually freezes. I have landed at Vancouver Intl in the 737 900 NG manually, but have not tried yet to manually land at Seattle Intl. I have the HighMem fix in the Config files and have explicitly followed the setup recommendations in the Intro Docs including setting the textures to 4096. (by the way you talk about HIMEM ? and not Highmem ? - which is it??. I have set my scenery to Dense rather than normal as frankly normal looks unreal and part of the joy of flying is to have a semi real appearance out the window. This all hints to some kind of memory leak to me, and I have read about this possibility for windows 32bit, but not for Windows 64 bit for this aircraft? I have an i5 overclocked to 3.2 , 4 Gigs 1600 ram, GTX EVGA 460 1mb graphics card, running Windows 64bit. I use Orbx PNW for the area, FSrealWX freeware for the weather, Ultimate Traffic 2 set at 50 percent for AI traffic and I am running the latest NVIDIA beta drivers 280.19 Any positive feedback most welcome Ray

Update;I used Frame limiter and set it at 30 FPS. I then loaded another scenario (I have two saved for ILS approaches to KSEA) and ran the approach again. This time I managed an ILS landing without a CTD - but ended up with a brake lock on the runway. I did notice that once the ILS G/S diamond started down and hit the pip one above centre position I used G to lower the gear. The gear animation lever was very very jerky and slow and I thought "here we go again" - but it recovered and I was able to make the landing. I do not know if adding Frame limiter has assisted me in making this ILS approach and landing without a CTD or not, so I would be interested in any feedback

Not to sure, iv done an ILS no problem. as for the brake lock, you have to double tap your brakes to disengage the autobreak

For the last few years, I have not been able to fly anywhere near KSEA without a fatal error. Any plane any time of day or season any setting. There must be something triggering it. If I give a 50nm birth around Seattle, I'm fine.

Thanks for the replies ...Nope the frame locker was a red herring. Just had another CTD.This time I was at 5900 feet heading past KSEA for a Southern approach to 34 Centre. I was busy fiddling with the FMS to find the line that gives you the match for your Throttles on the display when you disengage Autothrottle - when suddenly it froze. I had the FMS up in the zoom position ..... I should do what you have done ricky76 and give seattle a wide berth. Perhaps the Orbx version of Portland city and environs will be better?? I do like Friday harbor though... and often start Ant's Sierra Tecnam from there - or the bird dog... I am beginning to think perhaps it is the 3rd party AFCAD I loaded to give me the 3 runways for KSEA?? (Although I have been using this AFCAD for a couple of years now ??)Might just give that a try and delete it and see.. Ray