I was building a site based on Plain Yogurt theme. HeaderNav was working correctly.

I changed the theme to a customized Green Salad. HeaderNav now displays in reverse Sitemap order. I've tried various options under "Pages Should Appear" in the HeaderNav Edit popup, without success. It's "stuck" in reverse Sitemap order. Sidebar nav displays correctly.

I changed the theme back to the original, and HeaderNav display order is correct. Changed it back to the new theme... it reverts to the incorrect, unchangeable order.

What now?