new lines in <pre> blocks in xml/xhtml output

[Marie Sauvage - EBM WebSourcing <marie.sauvage@ebmwebsourcing.com>]

Hi !

I have a problem with output in xml/xhtml mode : the generated source go to new line too often.
Better than explanation here are the codes :
My docbook source :
              <screen>
              a simple <emphasis role="bold">test</emphasis> screen
              a simple test screen<co id="simple-test-1" />
              a simple test screen
              </screen>

The html output in mode="html" :

<pre class="screen">

              a simple <span class="bold"><strong>test</strong></span> screen
              a simple test screen<a name="simple-test-1"></a><img border="0" alt="1" src="../../resources/images/callouts/1.png">
              a simple test screen
              </pre>

The html output in mode="xml" (or mode="xhtml") :

              <pre class="screen">
              a simple <span class="bold">

<strong>test</strong>
</span> screen
              a simple test screen<a name="simple-test-1"/>
<img border="0" alt="1" src="../../resources/images/callouts/1.png"/>
              a simple test screen
              </pre>

Resulting problem is that when viewing the page with browser, there is many line breaking and code isn't understandable.
I'm trying to compare html and xhtml stylesheets from docbook but don't find where the problem can come from and how to solve it. Does anyone have an idea ?

Thanks in advance,
Marie.