I was trying to format the layout of the Custom Query Webpart similar in fashion to instructions found at http://www.heathersolomon.com/blog/articles/CustomItemStyle.aspx.
The problem was that no matter what I did in CQWP based on the announcements list the title and image appeared but the body text was not showing up.
After reading a few articles including http://martijnmolegraaf.blogspot.com/2008/12/configuring-and-customizing-content_20.html I realised that body was a custom field and so I needed to export the webpart.
Edit the exported webpart file with all my custom fields.
The line to edit looked like
<property name="CommonViewFields" type="string">
Note the name followed by datatype.
Then import the webpart back in and use it as you would any other CQWP.