windows 8 - Preserve FlipView selected item on GoBack navigation? -

i have app 2 levels of layoutaware pages flipviews. goback causing me headaches since remembers original navigation parameter instead of saving last state when navigated away from.

navigation flow:

1) mainpage:

selecting item navigates flip view page current item selected: this.frame.navigate(typeof(itemflipviewpage), selecteditem1);

2) itemflipviewpage: set flipview selected item based on loadstate navigation parameter (selecteditem1 in example)

change flipview's selected item (for example selecteditem3) , navigate galleryflipviewpage:

this.frame.navigate(typeof(galleryflipviewpage), selecteditem3_image1);

3) galleryflipviewpage:

clicking goback button causes itemflpviewpage loaded original navigation parameter of selecteditem1.

what's best way preserve selected item on goback?

set page.navigationcachemode="required".