Multiple menus on each multisite won't refresh

Hello,
I’m having a problem with my multisite.
We are having 5 different sites, and one home page in the multipage installation. Each of the sites have their own menu. But when navigate from the home page that is http://www.mysite.com to the other multisite that is http://www.mysite.com/site2 , the main navigation for http://www.mysite.com still stays at http://www.mysite.com/site2. When i press the refresh button the menu changes to the one belonging to http://www.mysite.com/site2. This happend for all the pages.

How can this menu change automatically without pressing reload button?

Hope anyone can help me out with this:)