Navigation with tabs buggy in beta 12

In the actual beta the navigation with tabs is buggy or do I make some thing wrong?

See this sample:

If you go to the Friends Tab you can open a Friend an close it again with the back button. But if you open your best friend form the Dashboard you won’t get a back button. How can we fix this?

A second problem is if you are opening a friend in the friends tab, leave it open an go to an other tab with the tab navigation for example dashboard and then go back to the fiends tab the opened friend is still there whats actually good. The only problem is that the title is not shortened any more:

I this a known problem?



I got the same second issue.
[update] See my post Two states in the same view contained in a tab replace the nav tab link