menu sub-page order

I have Frisco, but this is more a generic, non-item-specific question.

On my main menu for one of my page icons there I want to have four sub-pages. I want them to appear in the drop-down box in a specific order, 1-2-3-4.

I have tried to do this dozens of times by going via:
Dashboard>Pages>All pages>Page Attributes to the Order box at the bottom. I put in 1 for one of the subpages, then go to the next subpage & enter 2, etc.

After finishing that I go back to View Site and click on the Books page icon, in the drop-down box it always comes up in.the.same.order! How do I change that order? This is necessary because their relative importance requires them to be in a certain order. How do I change the order in which they appear?

Thanks.