Hi,
Loading up your airport ICAO in AFX will show all active files. I've had it happen several times that an old version I forgot about was still active as well...
In FS9 the aircraft radius (not wingspan) is defined in the .mdl file, not the .air file, IIRC in meters.
AFCAD2 and AI-Aircaft Editor (and probably others...) can make those changes to the .mdl file.
In ADE options one can choose to use ft. or m. for parking.
Also, parking spots have an order index, which can be seen and changed in ADE, or AFX.
If you create a new parking spot it's index is added to the end of the line. So that spot will be filled last, but still taking into account the aircraft radius and airline code...
Screenshot from ADE1.65 manual.pdf
When I redo an airport (with ADE), I always reorder the parking spots in the index table, from small to large. Then depending on the airport, I can reorder same radius spots, gates first, then ramp. E.g. all my B737/A320s will fill the gates first, and only then the ramp spots.
Regards,
DDP.