How can i add multiple users in my forum?

Hi,

I recently installed punbb in my website and it's great, but i need to add a lot of users and put them on a certain group to access some restricted forums, it can't be done by them because i don't trust a user asking me for access.

I tried to add some users in punbb but after the first one i got a message saying to wait one hour before adding a new user.

I searched in the configs but didn't find anything to take this off, so how do i disable this?

thanks in advance for any help.