Facebook bug retrieving vCard?

Issue: the facebook XMPP server no longer responds after trying to retrieve a self or user vCard.

This the code sent to the server:
<iq id='1' type='get'><vCard xmlns='vcard-temp'/></iq>

as described in the facebook developer chat reference.

The issue persists both using MD5-DIGEST or X-FACEBOOK-PLATFORM Sasl authentication mechanism. Maybe a bug? Waiting a response from facebook technical support.