I use this code:

<?xml version="1.0"?>
<document filename="test.pdf">
  <template pageSize="(595.0,842.0)" title="Test" author="... " allowSplitting="20">
    <pageTemplate id="first">
      <frame id="first" x1="15.0" y1="42.0" width="539" height="758"/>
    </pageTemplate>
  </template>
  <stylesheet>
    <blockTableStyle id="Standard_Outline">
....
    <story>
        <para>
            [[ company.logo and setTag('para','image',{'width':'100','height':'100'}) ]][[ company.logo ]]
        </para>
        <para>
            [[ company.logo and setTag('para','image',{'width':'100','height':'100'}) ]][[ company.logo ]]
        </para>
        <para>test output</para>
    </story>
    </document>

The pdf file contains 2 pictures, but not the text "test output".

log file content: (no errors or warnings)

2013-05-24 12:50:04,466 3635 INFO db1 werkzeug: 127.0.0.1 - - [24/May/2013 12:50:04] "POST /web/action/load HTTP/1.1" 200 -
2013-05-24 12:50:07,210 3635 DEBUG ? openerp.report.render.rml2pdf.trml2pdf: Image is 239x58
2013-05-24 12:50:07,816 3635 INFO None werkzeug: 127.0.0.1 - - [24/May/2013 12:50:07] "POST /web/report HTTP/1.1" 200 -