I'm using vbulletin 4.2.3.
I got it to work. Thank you for the Mod

I thought it didn't work at the start, but then I realised you must enable it from usergroups (
this isn't in the screenshots in the original post).
These are my settings:

^ I honestly don't have a clue what that setting does.
Mind telling me Nick?
AdminCP -> Usergroups -> Usergroup Manger -> [Select Group]
Right at the bottom:
Once installed, 'Members' Navtab didn't appear. It only appeared after I changed the setting to yes from usergroup (^administrator) & pressed saved on 'Members' from the Navigation Manger:

^ That's the default settings. If you don't see some of the fields, then you still need to change your usergroup permissions to yes.
If you can't make it work, I suggest doing exactly as I've done (same settings) in this post.
@Nick
P.S= I suggest having a installation guide either as a installation text file OR written down in the original post.
Also include a screenshot of the
this in the original post.