Well, finally, I have found it :-)
I generated and did read your couatl.log, and I noticed that it listed only default entries in my scenery.cfg, no mention to any of the rest of my addon airports.
To cut a long story short, I don't use FSX Scenery Library to edit my scenery.cfg, I do it by myself, mainly because it is the way I can make sure I avoid all conflicts between sceneries. I like to order them correctly: First of all meshes, then VFRs and autogen, and after that, all airports (inverse order than FSX shows them at scenery library).
Also, I do some testing from time to time before declaring a scenery ready to use, so I comment some lines of my scenery.cfg. Usually you can disable a scenery by two different ways. You can change the "active" value to FALSE, or you can place a semi colon ";" before all lines in that entry, because FSX simply ignores them.
I also use semicolons to comment different sections in my scenery.cfg (for example, they are arrenged by country, and I insert a line before them with their country name).
Well, GSX simply ignores the rest of the scenery.cfg when it founds a semicolon. You can guess I have one before the very first of my sceneries, to remaind me that line is the beginning of addon entries.
Once I have removed all semicolons in my scenery.cfg, everything began to work like a charm.
That explains also what I've told you several times, that is FSX places the aircraft at the right position, but GSX don't think it is a right one, only because it is not aware of the scenery, reason why it tooks stock BGLs.
Maybe it is also the answer to the problem reported on 2012, I have included in my last post.
And you are using FSDT KLAS ? Sorry, but that's just not possible, especially after an FSX cache rebuild, because that AFCAD WORKS.
Well, that AFCAD works perfectly when it has the opportunity to do it. And, oh, yes, of course I AM using FSDT KLAS.
Maybe could we expect a fast update from FSDT, that will allow GSX parsing process to ignore scenery.cfg lines beginning with a semicolon?
Regards ;-)