I'm using Mac OS X. When I try to open a letterbox file, the program, by default, looks for "Letterbox Files", and it doesn't treat my files, which are ".txt" as such (i.e. I can't select them in the open file dialog). So I change the dropdown to show "All Files" and then I can select the file I want.
Is there a default extension for letterbox files i.e. *.lbx?
