[business theme] global menu divided top/bottom

Well, as I'd like to use business the for one of my farms, I have a strange issue :

Config of this farm : WPMU 2.9.2 + BP 1.2.3

the BP menu (home, groups, members, blogs, activity, forum) isi divided :

home and about come at the top, members, blogs, forum and groups at the bottom of the page.
Is it normal ? On the business manual, all seems to appear at the top of the page !