Problemas with fail2ban

[Martin Marques <martin@bugs.unl.edu.ar>]

I started seeing that fail2ban is not working properly on my debian 
server, while working in other places where I'm using other distros.

I started searching and found this in the logs after putting in 
debugging and restarting fail2ban:

2007-10-07 10:03:12,744 fail2ban.actions.action: DEBUG  iptables -N 
fail2ban-ssh
iptables -A fail2ban-ssh -j RETURN
iptables -I INPUT -p tcp --dport ssh,sftp -j fail2ban-ssh
2007-10-07 10:03:12,748 fail2ban.filter.datedetector: DEBUG  Sorting the 
template list
2007-10-07 10:03:12,752 fail2ban.actions.action: ERROR  iptables -N 
fail2ban-ssh
iptables -A fail2ban-ssh -j RETURN
iptables -I INPUT -p tcp --dport ssh,sftp -j fail2ban-ssh returned 200


What does the error mean? The fail2ban-ssh chain exists in iptables:

Chain fail2ban-ssh (0 references)
target     prot opt source               destination
RETURN     all  --  anywhere             anywhere

But fail2ban doesn't block when I get up to 7 fails from the same IP, 
while I have it configured to ban at 3.

Any ideas?