Then I noticed that nautilus is not displaying right the "index.theme"
files in the theme directories of in ~/.theme. Nautilus displays the the
name of the theme instead of the file name. Well, this wouldn't be so
bad, but this way I am not able to open the file 'normally' with a text
editor. What is nautilus doing there? Is there a way to change this
behaviour?
This is because the file is a desktop file. These are used for things
like menus and shortcuts in the free desktops. So, we display the name
listed in them, not the filename. You should still be able to open them
correctly with the open-with context menu.