Have you ever noticed THIS ?

[bakaman 28]

HI caps,Yesterday i've notice something very weird; the reg numbers in the fsx menu do not match the one on the fuselage, same story for the reg number on top of the fmc screen. Some planes pick up reg number from others planes even when they are not even installed or used to be in my library.thanks for your help.

[Steven_Caffey 23]

I had this problem before, Ryan suggested to delete all the NGX folders at the following location (assuming Windows 7):(your username) > AppData > Roaming > Microsoft > FSX > Sim Objects.Then start FSX. That fixed it for me. I also had the problem that since the reg didn't match, panel options weren't right either.

[scandinavian13 5,192]

If I remember correctly, you should ignore what's written in the FSX aircraft menu in terms of the callsign. Furthermore, you shouldn't alter it. I could be dreaming something up, but I recall someone saying it's used for something in the background.

[bakaman 28]

I had this problem before, Ryan suggested to delete all the NGX folders at the following location (assuming Windows 7):(your username) > AppData > Roaming > Microsoft > FSX > Sim Objects.Then start FSX. That fixed it for me. I also had the problem that since the reg didn't match, panel options weren't right either.

Thanks a lot ! Ryan advised this method as well: worked great !