Hi friends
I may have found a solution to the spammers problem and the change I had to do to the registrations to the site, that now are (were) very complicated.
I changed the forum settings in the way that each one of the forum is a "moderated" forum and everyone who writes in it needs an approval from a staff member (actually only me) before the post will be displayed normally.
Each user can be added to an "auto approval" list, it means that when he or she is added he or she doesn't need approval anymore, he or she goes to "normal" state.
So I switched all forum to "moderated" and added all the active users to the "auto-approved" users list (you should have receive a PM about it).
In this way when a new users post for the first time I can see what he or she post, if it's spam -> ban, on the contrary if it's a normal post I'll move the user to the autoapproved list
Actually I'm the only one that can approve users, if you want to help me, tell and I'll add you too (thank you )
I've to find a similar solution for the album and maybe for the shoutbox if someone is so persistent.
We'll see, however keep an eye opened, all of you have the moderators privilege to move post and topics