Problem with generate-id() with stylus

I use the following code for each figure :
<xsl:template match="figure">
	<a name="{generate-id()}"/>
</xsl:template>

and for the figurelist :
<xsl:template match="figurelist">
<p>Figures :</p>
<xsl:for-each select="//figure">
	<a href="#{generate-id()}">
		<div style="margin-top: 1em">
			<xsl:apply-templates select="caption"/>
		</div>
	</a>
</xsl:for-each></xsl:template>

An extract from my xml file is :
<frame id="nb2h1u1v">
<figure size="0">
<caption>Blablabla</caption>
<graphic content="36226001.gif" notation="gif" pos="276,0" size="0" picnum="1"
view="0,0,1000,1000" orient="0" depth="1" pagewide="1" width="13cm"/>
</figure>
</frame>