The second I activate GSX at the airport everything in a small radius disappears.
As I've said, several times already (and posted many screenshots about it), it doesn't happen here, using the same airplane you use and the same parking.
But not only that, it simply shouldn't happen because, even if there was a problem with GSX in your system that would cause GSX crashing after having selected it, you should have seen KORD *buildings* to disappear, not the taxiway signs, which in this scenery are handled by the Addon Manager instead.
More recent sceneries, like KDFW, have a feature that ALLOWS GSX to remove smaller objects around a parking when you select a parking in GSX, but KORD doesn't use it, so GSX cannot remove them.
Do you have the "View Optimization" option enabled in the Addon Manager ? That option is turned OFF by default, and it's best to keep it that way, it was just used to help fps with low-end systems. But again, that option would affect objects regardless if you use GSX or not.
You might also try to remove your FSX.CFG file located under %APPDATA%\Microsoft\FSX, perhaps there's a tweak you added which shouldn't be used.
