no ftp to public IP, only localhost works

[thosmos]

I am unable to ftp the public IP/domain of my server, even from itself, though i can ftp to localhost as any domain user. proftpd is set to run from inetd. domain name resolution works fine, /etc/resolv.conf is set to my local dns server, etc. /etc/hosts has the primary domainname set for public IP, but I cannot ftp to that domain either.

Any ideas?