Your e-mail confirmation system has several flaws:
- at least with Tiscali even if you press the link confirming the e-mail the process apparently work but evidently i confirmation don't stick as the pop up requiring the confirmation reappear nextr time you log in (and the workaround someone suggested don't work, you can do it when you ar elogged in or when you are unlogged, the result is the same);
- some provider security system remove the link, it is necessary to implement a alternative system if you want to get the confirmation from all the users.
So, there is some back up system to confirm the e-mail?