I think this notification area bug is not a duplicate of the bug 741387,
because that has been already fixed with the update of ubuntu-mono_0.0.27.
However, notification area is still broken.
I cannot see NM-applet icon there, just a broken icon image.
the only workaround is to downgrade libappindicator1 to the version 0.2.99-0ubuntu1.
I think this notification area bug is not a duplicate of the bug 741387,
because that has been already fixed with the update of ubuntu-mono_0.0.27.
However, notification area is still broken.
I cannot see NM-applet icon there, just a broken icon image.
the only workaround is to downgrade libappindicator1 to the version 0.2.99-0ubuntu1.