Xsl font size changes in explorer

Hi, anybody knows why using xml as xsl output method renders fonts larger than if I output as html ??? this only happens on explorer 6, firefox works fine…

This works wrong:

 <xsl:output
		method="xml"
		version="1.0"
		encoding="ISO-8859-1"
		indent="yes"
		doctype-public="-//W3C//DTD XHTML 1.0 Strict//EN"
		doctype-system="http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"
	/>

And this works fine:

 <xsl:output
		method="html"
		version="4.0"
		encoding="ISO-8859-1"
		indent="yes"
		doctype-public="-//W3C//DTD XHTML 1.0 Strict//EN"
		doctype-system="http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"
	/>

Thx in advance, i am working and totally stuck with this…