Authenticating against wordpress users

Hi There, I'm trying to setup ejabberd to authenticate against a wordpress user database on a separate server but am not having any luck.
I'm trying to use http://www.cubehouse.org/blog/2010/06/21/authenticating-xmpp-ejabberd-wi...
But end up with
=INFO REPORT==== 2015-04-01 01:31:36 ===
I(<0.367.0>:ejabberd_listener:281) : (#Port<0.2377>) Accepted connection {{CLIENT IP},33810} -> {{SERVERIP},5222}
=ERROR REPORT==== 2015-04-01 01:31:39 ===
E(<0.846.0>:extauth:133) : extauth call '["auth","username","domain.tld",
"password."]' didn't receive response
=INFO REPORT==== 2015-04-01 01:31:39 ===
I(<0.844.0>:ejabberd_c2s:649) : ({socket_state,tls,{tlssock,#Port<0.2345>,#Port<0.2374>},<0.843.0>}) Failed authentication for username@domain.tld

Is there another method or an easy way to get this working?
I'm not sure what's broken or why it's not working.