Please see the most recent updates in the "Where did the .com name go?" thread. Posts number 16 and 17.
This should only happen to Air files if you actually open them with Adobe Air. If you leave them alone, you are fine.
To open a Flight Sim airfile, if you are curious, use the freeware Airfile editor 'AirEd.exe' (google it and I am sure you will find it). Great little program.
I have heard stories of people unable to delete planes from FSX because the airfile was corrupted. That was really wierd. I wonder if this is a Win7 thing.
Bill
