Well, this has happened to me more than once!  The problem is, you saved a flight with those settings, so any subsequent flight will load the same way.  To change it, set everything how you want it and then press "Alt" to get the menu bar and select "Save Flight" from the "Flights" menu.  Name it whatever you want and then click the box "Make default flight".  Now quit and reload FS.  Start a flight, and it should be how you left it.