Doctrine_Table getTable singleton issue

first, i defined a table class :
class CohibaClientTable extends Doctrine_Table
{
public $_pager;

public function getAbstractList($arrParam = array(), $page=1, $maxPerPage=20)
{
$objQuery = $this->createQuery('t1')
->select('t1.*');

if(is_array($arrParam) && count($arrParam)>0)

{ QueryAssistant::processOption($objQuery, $arrParam); // dont set "offset" and "limit" option in it }

$this->_pager = new Doctrine_Pager($objQuery, $page, $maxPerPage);

$items = $this->_pager->execute();

$objQuery->free();
return $items;
}

public function getList($page=1, $maxPerPage=20)

{ $arrParam = array( 'orderBy'=>'t1.cle asc' ); return $this->getAbstractList($arrParam, $page, $maxPerPage); }

public function getPager()

{ return $this->_pager; }

}

and then, in the action, invoke it like this codes:
1>
$items = Doctrine::getTable("CohibaClient")->getList(1, $maxPerPage);
$pager = Doctrine::getTable("CohibaClient")->getPager();

$this->log("total records: ".$pager->getNumResults()." total page: ".$pager->getLastPage()."\n");
$lastPage = $pager->getLastPage();
2>
$table = Doctrine::getTable("CohibaClient");
$items = $table->getList(1, $maxPerPage);
$pager = $table->getPager();

$this->log("total records: ".$pager->getNumResults()." total page: ".$pager->getLastPage()."\n");
$lastPage = $pager->getLastPage();

#2 works, but not #1, error is "Fatal error: Call to a member function getNumResults() on a non-object in.... " is it an issue when singleton generation?