Cannot create socket to [localhost]:2812 -- Connection refused

Hey,

after i setup monit and check it with monit status there is this error: Cannot create socket to [localhost]:2812 -- Connection refused

Code:

set httpd port 2812 and
     use address localhost  # only accept connection from localhost
  allow localhost        # allow localhost to connect to the server and
  allow admin:monit      # require user 'admin' with password 'monit'

(changed my real name and password)
Can anyone help me?

EDIT:
I add to iptables:

Code:

ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:2812

And then save it, but it worked like 15minutes and now the port is closes, but the rule in iptables is there