See Header/Footer Settings Recap and How to set up a document with front matter 2007.

Different odd and even headers/footers is a document not a Section setting. If you want different odd and even headers/footers in one section you must do so for the entire document. That means that if you want the same headers / footers on even and odd pages in 2 sections and different even/odd in one section, in the two sections you will need copy the one you already have into the blank one.