Jan, look at the XML below. Are you sure this is ok? Because the 'Select Guestbook' parameter seems to be different than the other ones. They are between <params> and select guestbook isn't.
If the file is ok, is there another way to set these parameters? By hand within the database for example, so I can use Phoca Guestbook in the end.
<?xml version="1.0" encoding="utf-8"?>
<metadata>
<layout title="PHOCAGUESTBOOK LAYOUT">
<message>
<![CDATA[PHOCAGUESTBOOK LAYOUT DESC]]>
</message>
</layout>
<state>
<name>PHOCAGUESTBOOK LAYOUT</name>
<description>PHOCAGUESTBOOK LAYOUT DESC</description>
<url addpath="/administrator/components/com_phocaguestbook/elements">
<param name="id" type="phocaguestbook" section="com_phocaguestbook" default="0" label="Select Guestbook" description="Select Guestbook" />
</url>
<params>
<param name="show_pagination" type="radio" default="1" label="Pagination" description="Show/Hide Pagination support">
<option value="0">Hide</option>
<option value="1">Show</option>
</param>
<param name="show_pagination_limit" type="radio" default="1" label="Display Select" description="Show/Hide the Display Select dropdown">
<option value="0">Hide</option>
<option value="1">Show</option>
</param>
<param name="show_feed_link" type="radio" default="1" label="Show a feed link" description="PARAMSHOWFEEDLINK">
<option value="0">Hide</option>
<option value="1">Show</option>
</param>
</params>
</state>
</metadata>
)