[xslt] xsl:number level="multiple"

["Sebastian Rahtz" <sebastian rahtz computing-services oxford ac uk>]

consider

<a>
 <a>
   <a></a>
   <a></a>
 </a>
 <a></a>
</a>

processed by 

  <xsl:template match="a">
    <xsl:number level="multiple" format="1" />
    <xsl:apply-templates/>
  </xsl:template>

The libxslt output is 1 11 111 112 12, which is surely not right?

Sebastian