I'm trying to get the text from a radiobutton list but am getting an XSLT error:

<xsl:param name="currentPage"/>

<xsl:template match="/">

<!-- Create filter box -->
<div id="filterBox">
  <form id="filter">
  <fieldset class="category">
    <legend>Filter by Category</legend>
    <label class="label_radio"><input type="radio" name="type" value="all" checked="checked" />All Categories</label>
    <xsl:variable name="prevalues" select="umbraco.library:GetPreValues(1187)" />
        <xsl:for-each select="$prevalues/*">
          <xsl:sort select="."/>
          <label class="label_radio">
             <input type="radio" name="type"><xsl:attribute name="value">
                <xsl:value-of select="." /></xsl:attribute><xsl:value-of select="." />
             </input>
          </label>
        </xsl:for-each>
  </fieldset>
</form>
</div>

<ul id="clubList">
<xsl:for-each select="$currentPage/* [@isDoc and string(umbracoNaviHide) != '1']">
    <li>  
    <xsl:attribute name="data-id">id-<xsl:value-of select="position()"/></xsl:attribute>
    <xsl:if test="./clubCategory!=''">

      <!-- This is where the macro fails, its doesn't seem to like the GetPreValueString -->
      <!--<xsl:attribute name="data-type"><xsl:value-of select="umbraco.library:GetPreValueAsString(clubCategory)"/></xsl:attribute>-->

      <!-- Although it will return the correct clubCategory ID from the radiobutton list -->
      <xsl:attribute name="data-type"><xsl:value-of select="clubCategory"/></xsl:attribute>

      </xsl:if>
    <a href="{umbraco.library:NiceUrl(@id)}">
      <xsl:value-of select="@nodeName"/>
    </a>
    <div class="clearBoth"></div>
    <div class="clubListing">
    <img src="{concat(substring-before(umbracoFile,'.'), '_clubThumbnail.jpg')}" class="right clubThumb" alt="{alternateText}" title="{alternateText}" width="120px" height="75px" />
    <p><xsl:value-of select="snippetText"/></p>
    </div>
  </li>
</xsl:for-each>
</ul>

</xsl:template>

<li data-id="id-1" data-type="28"></li>
<li data-id="id-2" data-type="29"></li>
<li data-id="id-3" data-type="28"></li>
<li data-id="id-4" data-type="31"></li>
<li data-id="id-5" data-type="32"></li>