title: Cakephp find(list) issue
body: <p>when i am trying to fetch data from following query</p>
  
  <pre><code>$this-&gt;ZipCode-&gt;find('list',array(
                                  'fields'=&gt;array('ZipCode.id','ZipCode.city'),
                                                         'conditions'=&gt;array('ZipCode.province_id'=&gt;$province_id)
                                              ));
  </code></pre>
  
  <p>It works fine but when do something like this.</p>
  
  <pre><code>$this-&gt;ZipCode-&gt;find('list',array('fields'=&gt;array('ZipCode.province_id','ZipCode.city'),
                                              'conditions'=&gt;array('ZipCode.province_id'=&gt;$province_id)
                                              ));
  </code></pre>
  
  <p>an empty array returns. is there any problem in my query.??</p>