A person on the facebook page is having the same problem as me:
Trying to log in to the Creatures forum for the first time in a long time and can't remember my password. When I type in my user name and email address to resend the email it tells me that my password and user name don't exist. When I try to re-register it tells me that someone is already registered with my email address (me!), and my user name is definitely right. Anyone know where I can get some technical support on this - can't find anyway of getting in touch with them on the website
She then tried to use the email retrieval feature, which didn't work for her, too.
The official response was:
...Please be so kind and contact us here via private message and provide us with your login name and your e-mail address. We'll then take care about this issue and come back to you as soon as possible. ^ic
I think I'll do the same thing - just in case anyone else is having trouble with the official forums. 