I've tried to include custom gateways via mod_xml_curl. 

The request is correctly issued by mod_xml_curl and received by the backend:

"hostname=fire&section=directory&tag_name=domain&key_name=name&key_value=user&Event-Name=REQUEST_PARAMS&Core-UUID=18b2b698-c487-11e3-bcc9-39daad6bb1f3&FreeSWITCH-Hostname=fire&FreeSWITCH-Switchname=fire&FreeSWITCH-IPv4=192.123.321.123&FreeSWITCH-IPv6=%3A%3A1&Event-Date-Local=2014-04-15%2012%3A48%3A57&Event-Date-GMT=Tue,%2015%20Apr%202014%2010%3A48%3A57%20GMT&Event-Date-Timestamp=1397558937493970&Event-Calling-File=sofia.c&Event-Calling-Function=config_sofia&Event-Calling-Line-Number=5174&Event-Sequence=1510&purpose=gateways&profile=user"

The backend interprets the request by "purpose=gateways" and "profile=user" to send back all gateways required for profile "user"

<document type="freeswitch/xml">
<section name="configuration">

<include>
<gateway name="user_gw_1_foobar">
<param name="username" value=""/>
<param name="password" value=""/>
<param name="proxy" value="foobar.example.de"/>
<param name="register" value="false"/>
<param name="expire-seconds" value="300"/>
<param name="ping" value="300"/>
<param name="retry-seconds" value="300"/>
<param name="context" value="default"/>
<param name="caller-id-in-from" value="true"/>
</gateway>
</include>

</section>
</document>

I've tried to remove "document", "section", "include" but no effect. 

Removing all gateway xml files from local filesystem does not change anything, either.

Unfortunately the wiki https://wiki.freeswitch.org/wiki/Mod_xml_curl#Example:_purpose.3Dgateways does not give a proper example

Thx and regards
Daniel