WordPress cannot publish post anymore, just set them in pending status

Hi everybody,
recently I’ve upgraded to WP3 (network mode enabled) and everything went fine.

But on last days I’ve got a problem: no one of my editors neither administrators can publish anymore.

Every post they try to publish go in “pending” status and rest in that status until I publish that with network administrator account.

To check I installed a “role” plugin and the capabilities are all ok, exactly as described in https://codex.www.ads-software.com/Roles_and_Capabilities .

I cannot understand what’s wrong. Anybody experienced the same problem or have a suggestion to solve?

Thank you very much,
Carlo

EDIT:
Actually a user can publish only if have the “Grant this user super admin privileges for the Network” on, even if it’s just a subscriber.
On the otherside without the flag neither an administrator can publish, but can just put posts in “pending review” mode.