Email Confirmation NOT working. BUT... ?!

Hi,
J! 1.5.23 + CB 1.7
Originally, I tried the CB registration after install and it worked fine: in my mailbox i still have the confirmation email.

However, I tried again (sometime later since the web is under development, nobody has been using it) and it's not sending emails. I browsed a lot looking for a solution and so far i've done the following:
-use as Mailer all PHP, SMTP and Sendmail. All worked fine with joomla mass mail but not with CB Resend Confirmation.
-tested password and user reminder AND IT SENDS EMAIL! (to users already signed up)

I tried changing the PMS (UddeIm) settings, maybe it was that, but those work fine.
I tried Unpublishing all the CB plugins to see if maybe something i added had done it. But the same happens with them on and off.

If anyone can shed some light on this issue i would appreciate it a lot
(have spent too much time looking through the web and changing settings, because i know nothing about coding)
Thank you

Using the CB User Manager i can even send 'Mass Mail' to those users it refuses to send the confirmation email to.
Isn't this really really weird? Isn't there a simple solution for this? i mean, afterall everything works: registration and email sending, its just the confirmation email that doesn't want to work. But without it, users can't register.

Please, please, any advice?

Only thing I can suggest is to check spam box.

Spam box doesn't show them. When they do come in, using mass mail or the email saying they are accepted they both go to the main box as well.

ended up deleting CB

well i cannot replicate on all my test sites even a new one i created just to double check.