Ouch! There was a bug that affected locations in solar systems where the star isn't fixed. I'm surprised no one has found it so far--I guess that no one has every tried to create a multiple star system add-on where an orbiting planet had locations defined on it.
The bug manifested itself in our solar system because last night I changed the Sun so that it moves around the solar system barycenter.
It is fixed in CVS now.
--Chris