Please read again my last post:
If you disable the airport in the AEC utility, and you still have floating jetways, then you must have another scenery in conflict that has changed the altitude for the airport, which is causing the same effect as Orbx vector.
As I've said, this doesn't happen with only the default scenery installed so, it must be some addon you installed that has added a new AFCAD that has a different altitude AND it stays on a higher layer in the Scenery Library, so GSX correctly reads the altitude from there, it cannot possibly know if it's correct or not.
Ran FSDT Live Update, Windows Update and Installed new Nvidia drivers.
That's precisely the reason why you have this. Our latest update tried to FIX this, and now it reads altitude corrections files too, that didn't read before. But, of course, it cannot possibly know if they are correct or not, and it must respect the Layering priority, since it cannot possibly know when use the opposite layering priority.
Basically, it's a problem that cannot always be solved automatically.
That's why I said in the next update, you'll have the ability to override the altitude in the GSX customization page.