Hi, just wanted too add that i had the exact same problem. There are two different addon managers for those products. My solution was to make a copy of my fs9 folder, and rename it to fs9 off or whatever you want. Then installed the problem airport in the new folder , this results in a differen addon manager. Then i cliucked on my key file and added it to the registry. When i fired up fs9 the problem airport was in the addon manager but my other fsdt Airports showed as inactive. Going back to my original install all fsdt airports except the problem one were active. So long story short when i want to use the problem airport i use that folder, when i want the other airports active i use the original. Convoluted yes,but works for me. Regards, David