Change Cockpit view and lose AI planes on ground

This is an unusual problem. When in 2D panel or in W mode I lose my parked AI aircraft. In Spot view and VC they are all there. This occured after using these AI planes for a long time so it's not something new has been added.This occurs whether airborne or on the ground. I've checked the FS9.cfg and that's not the problem. All the parking places are there for the AI stuff. The flightplan I use at this airport has been in use for about 2 years. It's a mystery and I'm out of ideas.DAve