5
go into XOOPS admin, then user settings, find users and check 'Type of users to show' to 'Only inactive users' and then hit the submit button. This will find all inactive users in the system.
I think this past of XOOPS (Userside admin) is very weak and should be given some more thought and attention in the future. I find it annoying that I have to activate a user just to see his details etc first. I would also suggest loggin their IP address in the user database for future reference, with the possiblity of adding to the banned IP list.