Vista will not allow you to write to files in the Programs area. It therefore creates a virtual store (copy of the dta files from each program you run) so you need to find this area and you will see copies of the data files and these are the ones/area that you need to place all the copied stuff into.
EDIT - on my machine the path is
C:\Users\My name\Appdata\local\Virtualstore\program files\AirNav .... then it completely replicates what is in the main AirNav directory so set ip the Photos in the correct area of this virtual store.
Mike
I had no problems copying files to the Programs area. I had a couple of "Do you really want to do this" messages, but other than the long copy times discussed above, it just seemed to work like XP. All the expected directories were there in C:/Program Files/AirNav Systems/ etc when viewing with Explorer.
I copied D008.dat over from a USB memory stick, as well as NavData.db3, all contents from /Logos and /Flags. It was only the 16,000 jpg files in /Photo that gave me the time problem.
I was doing this as the Administrator. Maybe there are restrictions if you aren't working as the Administrator.