I figured it out. When something is wrong in your naml, the system "turn off" your tweaks in order to make the site working.
Your appearance setting (color, font, etc.) is a tweak and you had a naml error at gallery_table macro.
So every time you went in a site area that calls gallery_table macro, like your sub gallery, the naml used to brake and your tweaks ( font ) stopped.
I fixed that in your forum.
Please, always look at your advanced editor. Even though when you save a code it doesn't show any errors, when you pass by a broken area and back to the editor, the error will be shown.