OK, just dumb ideas since this has never come up before; and I have never changed my password before.
1. Are you changing your password from the "server" application? This really shouldn't matter.
2. Have you tried changing your password to something else?
3. When you say the old password doesn't work, do you mean you are simply trying to use it or did you switch back?
4. If not, try switching your password back to that one.
5. Have you closed and opened every application? You must have if you real the Fix it tool.
6. Have you tried uninstalling and reinstalling AC on the server? I would think that would work.
