Cannot access server on port different than 80

I'm hosting a server on Rackspace. Generally I have some domain name that i redirect to my ip and use nginx for the internal routing. This is my default configuration:

server {
    listen MY_IP:80;
    server_name MY_DOMAIN.com;

    location / {
        fastcgi_pass 127.0.0.1:8888;
    [...]

I have my webserver running on 8888 and it works.

I now need to directly expose my ip on a given port so that I can access the site for testing on

http://MY_IP:8111

but it doesn't seem to work. I have nginx set up like this:

server {
    listen MY_SERVER:8111;
    server_name _;
    location / {
        fastcgi_pass 127.0.0.1:9892;
    [...]

The webserver is correctly running on 9892. If i wget http://MY_SERVER:8111 from the server itself it work, but from the outside it simply refuses the connection until it timeouts.

I thought it was something with my IP table, but it seems correct:

   target     prot opt source               destination
   ACCEPT     all  --  SERVER_NAME          anywhere

   Chain FORWARD (policy ACCEPT)
   target     prot opt source               destination

   Chain OUTPUT (policy ACCEPT)
   target     prot opt source               destination

Can you help? Thanks