Why doesn't FSX know that I changed my Gamespy password?

I can't play it online now.

Well, first of all, Gamespy is a really crappy multiplayer provider. I would've chosen that FSX use its own service. If you don't know your pass, press I Forgot my Password in the login and type in your email address. your pass will be sent to you. If none of this works, make a completely new account. You can have multiple accounts on one email address. Hope this helps!