copy-of converts hex to decimal

Hi there,

can someone explain why xsl:copy-of converts hex values to decimal?
e.g. the node:

<HexDecTest>
    <Hex>&#x2160;</Hex>
    <Dez>&#8544;</Dez>
</HexDecTest>

is processed to:

<Result>
   <Hex>&#8544;</Hex>
<Dez>&#8544;</Dez>
</Result>

using this template:

<xsl:template
match="HexDecTest">
        <xsl:element name="Result">
<xsl:copy-of select="Hex"/>
            <xsl:copy-of select="Dez"/>
</xsl:element>
</xsl:template>

i expected the hex value unchanged,
matthias