[Dovecot] dovecot 1.2.5 - can't create auth listener

[dovecot]

Hi. I have version 1.1.11 working fine with multiple servers. When I upgrade
to 1.2.4 or 1.2.5 I keep getting an error 'can't create auth listener'
(address in use)

I have two ip addresses (lets call them 1.0.0.1 and 1.0.0.2).
Each ip address has it's own certificate and set of servers with custom
ports. I don't know how the configuration is supposed to work and it was a
lot of google and trial and error to get it working.

My configuration file is pretty basic so maybe someone can point out where
I'm going wrong. I stripped out the few comments and unrelated settings.

#listen = *
disable_plaintext_auth = no
ssl_ca_file = myca.crt
protocol lda {
  postmaster_address = postmas...@example.com
}
server a1 {
        protocols = pop3
        ssl_cert_file = a1.crt
        ssl_key_file = a1.key

        listen = 1.0.0.2:110 1.0.0.2:111

        auth default {
          mechanisms = plain
          passdb pam {
          }
          userdb passwd {
}}}
server a2 {
        protocols = pop3s
        ssl_cert_file = a1.crt
        ssl_key_file = a1.key
        listen = 1.0.0.2:995
        auth default {
          mechanisms = plain
          passdb pam {
          }
          userdb passwd {
}}}
server n1 {
        protocols = pop3
        ssl_cert_file = n1.crt
        ssl_key_file = n1.key
        listen = 127.0.0.1:110 127.0.0.1:111 1.0.0.1:110 1.0.0.1:111
        auth default {
          mechanisms = plain
          passdb pam {
          }
          userdb passwd {
}}}
server n2 {
        protocols = pop3s
        ssl_cert_file = n1.crt
        ssl_key_file = n1.key
        listen = 127.0.0.1:995 1.0.0.1:995
        auth default {
          mechanisms = plain
          passdb pam {
          }
          userdb passwd {
}}}
...and repeat for imap, imaps

Thanks,
Sean