PHP Fatal error: Uncaught exception 'MessengerException' with message '[-5]: no valid sources'

Sorry, but I don't know if it is really a bug or I'm doing something wrong.
There is no documentation for Proton PHP, so here I am.

Every time I try to execute recv.php sample I get this error:

[0x16d2180]:ERROR[0] (null)

[0x16d2180]:ERROR[0] (null)

CONNECTION ERROR connection aborted (remote)
PHP Fatal error: Uncaught exception 'MessengerException' with message '[-5]: no valid sources' in /usr/share/php/proton.php:61
Stack trace:
#0 /usr/share/php/proton.php(146): Messenger->_check(-5)
#1 /home/ubuntu/qpid-proton-0.7/tests/smoke/recv.php(20): Messenger->recv()
#2

thrown in /usr/share/php/proton.php on line 61

I've tried all of this command lines:

$ php recv.php
$ php recv.php "amqp://0.0.0.0"
$ php recv.php "amqp://127.0.0.1"
$ php recv.php "amqp://localhost"
$ php recv.php "amqp://localhost:5672"
$ php recv.php "amqp://localhost/myqueue"
$ php recv.php "amqp://localhost:5672/myqueue"

Where myqueue is my first queue created at Qpid 0.28 Web Console.

I'got the same Connection aborted on send.php but what is weird is when I run send.php against an ActiveMQ Apollo broker I have no error message and I can see for just one or two seconds one line referring my message sent to it at its web console. So I presumed that send.php is able to connect an amqp broker but I don't know why it doesn't connect to Qpid 0.28.

Please, What am I doing wrong, what are valid sources and where can I find more documentation about the Proton PHP library?
Even the proton.php and cproton.php created by Swig have no comments.

Thank you.