Changing NP++ Settings Don't Persist?

I just started using NP++ Portable, and - unless I'm doing something wrong - it doesn't look like it's saving the preference changes I've made after I've closed the program and opened it again.

i.e.

1) I open Notepad++ Portable
2) I go to SETTINGS > STYLE CONFIGURATOR... > LANGUAGE: PERL > (Change the syntax highlighting of scalars from ORANGE to BLUE
3) Click SAVE & CLOSE
4) Close Notepad++ Portable
5) Re-open Notepad++ Portable

When it's re-opened, the syntax highlighting for scalars in Perl is back to being ORANGE.

How do I make changes like these persist?

- Gary