I cannot access to nitrogen/inets server from any machine but the localhost

Thanks to many discussions in this forum, I found that I should be able to build the application I was planning to do for home usage based on Nitrogen.

So I ran into Nitrogen tutorials, Demo and docs, and start to do some tests based on the self contained inets/nitrogen site. Everything was going well until I wanted to try to access my new website from another PC. Of course I had to tune my box first in order to route wan requests to lan... But after a day searching, reading and testing, I am still stuck...

What I have tested:

• call the website from local host using intranet IP address or localhost: OK
• from local host, access to static pages and different "my_page.erl" path : OK
• access from another PC using lan address : I can catch the ethernet frames using wireshark, but the connexion fails with timeout.
• access from another PC using wan address : I can catch the ethernet frames using wireshark (after address translation), but the connexion fails with timeout.

• access from local PC using wan address : I can catch the ethernet frames out and in using wireshark but the connexion fails with timeout.
• I have put some ?DEBUG macros in my code: but none of them is reached.
• I tried an access to a static file: same behavior.
• I checked using netstat -ap that the process beam.smp is listening the right port: OK
• I checked for a response frame on external PC using smartsniff: no response for both lan and wan accesses.
• I tested different ports and port routing.

I must miss something obvious, is there something to configure in order to make this work? or a test I can do? because I have no more ideas.

context:

• browser firefox 16.0.2 and chromium 21.0.1138 running on windows XP 32
• server running on Ubuntu 12.04
• default nitrogen/inets application (modified port to 8020)
• Erlang 15B02
• nprocreg, 0.2.0
• parsetools, 2.0.7
• common_test, 1.6.2
• mnesia, 4.7.1
• ssl, 5.1
• public_key, 0.16
• compiler, 4.8.2
• xmerl, 1.3.2
• runtime_tools, 1.8.9
• crypto, 2.2
• inets, 5.9.1
• sasl, 2.2.1
• stdlib, 1.18.2
• kernel, 2.15.2

I enter this answer just to mention that the problem was in my firewall configuration as Syhpoon pointed it, and so it is solved.

To other members, what should I do with this question? I don't think it is a great help for other people apart that it is a reminder for all of us who are stuck to:

• List all the elements playing in the game
• "Ask a little help from my friends" ... not too late :o)

Should I delete the topic?