XSLT selecting attribute of ancestor; &ldquo;../..&rdquo; works, &ldquo;ancestor::<tagname>&rdquo; doesn't

<package name="blork!" xmlns="http://xml.snapin.com/XBL">
  <xsl:template name="doSomething">
    <tokens>
      <token name="text-from-resource" export="public" />
    </tokens>
  </xsl:template>
</package>

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:s4="http://xml.snapin.com/XBL">
  <xsl:template match="/">
    <xsl:if test="count(//s4:token) >0">
      <xsl:text>Tokens!</xsl:text>
      <xsl:for-each select="//s4:token">
        <xsl:choose>
          <xsl:when test="@export='global'" />
          <xsl:otherwise>
            <xsl:value-of select="translate(ancestor::s4:package/@name,$uc,$lc)" />
          </xsl:otherwise>
        </xsl:choose>
      </xsl:for-each>
    </xsl:if>
  </xsl:template>
</xsl:stylesheet>

<xsl:value-of select="translate(ancestor::s4:package/@name,$uc,$lc)" />

<xsl:value-of select="translate(ancestor::*[local-name()='package']/@name,$uc,$lc)" />