I cannot edit pages in my network

Dear friends,
I have a very strange problem: pages in my WordPress 3.2.1 Multisite network are not editable.

I can edit pages of my super admin site exclusively. I cannot edit edit pages in other child sites. There is also no admin bar and no visual menu there. There is the same problem for all my admins.

There is no problem for posts.

(I had problems with your Membership premium plugin. I hope that it is not a consequence of it.)

Pls help me.

Thanks,
Martin