I'm trying to start the debugger on a do-nothing web page, and I'm getting "Failed to connect to the client address ..."

The server is CentOS 5, with PHP 5.2.6 installed (which is unusual - CentOS 5 defaults to PHP 5.1.6, I had to track down 5.2 rpms from a third-party website).

But PHP 5.2.6 does seem to be running OK, at least the phpinfo page reports it as running OK, and my simple test page runs OK:

<?php
echo "hello, world!"
?>

But when I try to debug the page from a client machine, by clicking "debug" in IE7, I get the "Failed to connect to the client address ..." message.

The debug listener is running on the client machine - I see the antenna dish. And when I telnet from the web server to the client, I connect OK, and I see the green triangle show up on the antenna dish icon, and see "1 client(s)" in the tooltip.

The help pages on your website only go so far as debugging the communication, which is working, and provide no hints as to what to do if you get this error and the communication is not the problem.

Any ideas?

I changed debugger.hosts_allow=ALL in /etc/php.ini, and still saw the problem. I changed debugger.hosts_allow to not include my client machine, and saw a "not allowed" error message, so it's not the security settings.

I've been restarting apache with "apachectl restart", and that seems to be working.

From phpinfo.php: