recurring, intermittent, unwanted switching to top-down...

This one has me stumped, and today it's worse than I've ever seen it. I've had this problem off and on for a while, but tonight it actually interfered with flying because it was happening so much, so I thought I'd see if anyone else has experienced this.FS2004 switches from cockpit view to top-down view uncommanded, and sometimes back again. At first I thought that I had a bad switch in one of the hats on my CH USB Pro Throttle, but I deleted the key assignment from that controller and it's still happening. (I also verified that this assignment has not been made to any of my other controllers.)I am slightly suspicious of my GoFlight hardware; I'm not sure but sometimes this seems to happen right after I turn or switch something on one of my GF panels. However, I'm not at all sure about that.As far as I know nothing can command the top down view now in my setup other than a right-click on the screen, or via the Top-Down menu item.Does anyone have any ideas or comments about this?Many thanks,Dave Blevinshttp://www.flightfactory-simulations.com/h...ster_banner.jpg