This issue is related/duplicate of ZF-2431

[Based on ZF 1.5.2 code]

Such call: Zend_View_Helper_PartialLoop::partialLoop($viewScript, Zend_Db_Table_Rowset $rowset) will couse this:

public function partialLoop($name = null, $module = null, $model = null)
{ 
// ...
// ...  
    if (is_object($model) && method_exists($model, 'toArray')) {
        $model = $model->toArray();     

}

to be always true, because Zend_Db_Table_Rowset which is stored in $model here implements toArray() method. This method does this:

public function toArray()  
{ 
    // @todo This works only if we have iterated through
    // the result set once to instantiate the rows.
    foreach ($this->_rows as $i => $row) {
        $this->_data[$i] = $row->toArray();
    }
    return $this->_data;   
} 

So all rows in rowset are converted to array.

The side effect of this behaviour is that: $this->partialLoop()->setObjectKey('myObject')->partialLoop($viewScript, Zend_Db_Table_Rowset $rowset);

won't populate row object inside $this->myObject, which behaviour is in fact implemented in Zend_View_Helper_Partial::partial():

    if (!empty($model)) {
        if (is_array($model)) {
            $view->assign($model);
        } elseif (is_object($model)) {
            if (null !== ($objectKey = $this->getObjectKey())) {
                $view->assign($objectKey, $model);              // <== This line is never reached, despite we have called setObjectKey('myObject')
            } elseif (method_exists($model, 'toArray')) {
                $view->assign($model->toArray());
            } else {
                $view->assign(get_object_vars($model));
            }
        }
    }

Commentig out line 71 in lib/Zend/View/Helper/PartialLoop.php, it is "$model = $model->toArray();" makes object accessible insiade partial view via $this->myObject.

Cheers!