Description:
------------
$doc->preserveWhiteSpace = false;

works fine up to the point when I try to load external XML file.

why is it so important?

firstChild, previousSibling are DOMText so I have to use
getElementsByTagName() which is much slower...
especially when I know that the node I'm interested in
is firstChild (XSD schema)

the $pFileName points to XML file eg.
<Programmers>
        <Programmer>
                <firstName>&#321;ukasz</firstName>
                <lastName>Budnik</lastName>
        </Programmer>
</Programmers>

my DOM:
DOM/XML 	enabled
DOM/XML API Version 	20031129
libxml Version 	2.6.6
HTML Support 	enabled
XPath Support 	enabled
XPointer Support 	enabled
Schema Support 	enabled
RelaxNG Support 	enabled

Reproduce code:
---------------
// up to this point whitespaces are OK
// $doc->preserveWhiteSpace = false;
// load new DomDocument
$tmpXml = DomDocument::load($pFileName);
// preserve whitespaces
$tmpXml->preserveWhiteSpace = false;
$tmpNode = $tmpXml->documentElement;
$contents->appendChild($doc->importNode($tmpNode, true)));

Expected result:
----------------
<?xml version="1.0" encoding="ISO-8859-2"?>
<xhp><properties><Page>index</Page><Module>main</Module><contents><Programmers><Programmer><firstName>&#321;ukasz</firstName><lastName>Budnik</lastName></Programmer></Programmers></contents></xhp>

Actual result:
--------------
<?xml version="1.0" encoding="ISO-8859-2"?>
<xhp><properties><Page>index</Page><Module>main</Module><contents><Programmers>
        <Programmer>
                <firstName>&#321;ukasz</firstName>
                <lastName>Budnik</lastName>
        </Programmer>
</Programmers></contents></xhp>