Receives empty response but can add users to moodle

Hi,
I am using Joomla 1.6.6 and Moodle 2.0.2 (Build: 20110221)
It seems configuring of both systems is correctly done. but in system check I receive "Received empty response from Moodle".
I searched for this in all of forum and checked everything.
I forgot to mention I have installed these in Linux Mint and have no firewall installed.

An amazing thing is that in Joomdle at joomla side, I can export users of joomla to moodle. When I select one user from Users page and Clicking on "Add User to Moodle" it works and the user will be added to moodle.

So why other things is not working?

The fact that you have the error message suggests why things are not working. Different parts of Joomdle use different technical strategies to integrate. Eg Logon using SSO does not need to be working to pull data from Moodle and vice versaa.

Have a look at the FAQ to resolve the error message before you proceed onto other taks

I read FAQ page in Documentation and also read System health check.
But nothing is wrong.
I dont know where Can I start troubleshooting?
I am a developer, Can you help me starting debugging joomdle to know where things go wrong?

In far majority of the cases this error message is displayed when the URL is incorrectly entered into the Joomdle configuration tab.

Also, if the two 'servers' cannot talk perhaps because of firewalls, dns, etc. this error message will be displayed. But as said, almost always it is related to the url. When you go to moodle home page, what does the url resolve to? Do you have any redirections inside .htaccess?

Hi,
my moodle homepage address is http:// localhost/moodle/ and I entered this address in joomdle

Is there any other required fields in configuration rather than
moodle address
token
moodle version
?

You use localhost??

You have installed this locally? If so, you may not have all the libraries, etc. installed as part of your linux build. Do you have file_get_contents, curl, php xml-rpc? Also, what happens when you enter this url in the browser? What does localhost resolve to? Giving it is a linux machine, you will have an ip address that you can use and/or you could configure a local dns / hosts to point a dummy domain, say testing.com, to your local ip address.

If this is on a webserver somewhere, than you should not be using localhost. Instead you would have a public ip address that you should be using.

Check that you have enabled web services and xmlrpc on moodle, as failing to do so will show the empy response message.

As for debugging, you could just create a script in your webroot that loads moodle page via file_get_contents, so you can see if there are any connection problems.

Thanks to Chris and Antonio,

I installed joomla and moodle locally on a linux machine running PHP Version 5.3.2 on Apache.
my php has curl, xmlrpc and also file_get_content function.

I tried Antonio's method to debug and created a php file on my local server's root and put this content in it:
when I run this file(named file.php) on my localhost it brings the content of my moodle homepage.
What's wrong now?
Should I use http://127.0.0.1/moodle for address of moodle in joomdle configuration?

Try opening this address in your test script:
http://localhost/moodle/webservice/xmlrpc/server.php

I tried that but received this message:
 faultCode0faultStringAccess control exception