Second, it's driving me crazy... maybe I'm not that smart

I'm simply trying to create a customer and login with it. It seems to be impossible to accomplish this minimal task.
See my logs and what I'm talking about :
Thu Oct 6 23:16:07 2011 error OTRS-CGI-10 No UserID found for 'marcuoli_customer'!
Thu Oct 6 23:16:07 2011 notice OTRS-CGI-10 User: marcuoli_customer doesn't exist or is invalid!!! (REMOTE_ADDR: 192.168.77.11)
Thu Oct 6 23:15:59 2011 notice OTRS-CGI-10 CustomerUser: 'marcuoli_customer' changed password successfully!
Thu Oct 6 23:15:59 2011 notice OTRS-CGI-10 CustomerUser: 'marcuoli_customer' created successfully (21)!
I create the Customer but just can't login with it... What should I do ? I'm sure it's something very silly...
Thanks in advance.
Marcus