First, sorry for my english...
This is a fantastic plugin! Thank you!
Unfortunately it doesn't work in a multisite environment.
The "Super Admin" can network activate the plugin to make it available to all "normal" admins (blog owners). It works.
The problem is that "normal" admins cannot define where to show the tree. They see the link in their Settings menu but if they try to select an option (for example "Menu") and click on "Save changes", they get the following error:
You do not have sufficient permissions to modify unregistered settings for this site.
The settings set by the Super Admin should be applied side wide (i.e. for all blogs in the network). Normal admins should not see the CMS tree link in their Settings menu. In other words the settings would need to be set by Super Admin only. This would be the right way.
An easier alternative would be to set a default setting for the tree location (for example into the menu, and only for pages) while hiding the settings link to normal admins.
To the authors: Would you like to have a look at this? This kind of plugin is very valuable in networks, especially those aimed to non technical users.