title: Parameter returned as a Groovy String instead of the Object
body: <p>I have a custom taglib.  I am going to pass the result of the taglib into the g:render taglib.  One of the parameters is an Asset object.  If I call the taglib by itself it works fine.  The parameter is in fact an Asset Object.</p>
  
  <p>Example:</p>
  
  <pre><code>templateFinder template="_displayMain" findByFactory="asset" findByObject="${params.asset}"
  </code></pre>
  
  <p>The correctly renders the params.asset as an Asset in the templateFinder taglib.</p>
  
  <p>However once I add it to the g:render taglib it turns into the toString representation of the Asset object.</p>
  
  <p>Example:</p>
  
  <pre><code> render template="${g.templateFinder(template:'_displayMain', findByFactory:'asset', findByObject:"${params.asset}")}" ..../&gt;
  </code></pre>
  
  <p>This results in a Class Cast errorwith class 'org.codehaus.groovy.runtime.GStringImpl' to my Asset class.</p>
  
  <p>I am confused as to why this is rendering as an Object in the first example but a Gstring in the second.</p>
  
  <p>Thanks for any help. </p>