Yii 1.1 配置redis报错 [ 1.1 版本 ]

在服务器上配置redis,在服务器上是成功的，
当在项目config/main.php下是操作网上找的文档（http://blog.csdn.net/dc_726/article/details/8865340 ）配置的

components=>array(
.......
'cache'=>array(
    'class'=>'ext.redis.CRedisCache',     //对应protected/extensions/redis/CredisCache.php
    'servers'=>array(
        array(
            'host'=>'***.***.***.***',
            'port'=>6379,
        ),
    ),
),

'session'=>array(
    'class' =>'ext.PRedisCacheHttpSession.PRedisCacheHttpSession',
    'database' => 9,
),
)

当我访问我自定义的设置缓存的方法

public function actionFetch()
{
    $key   = 'key1';
    $value = 'key1value';
    Yii::app()->cache->set($key, $value);
    $data = Yii::app()->cache->get($key);
    var_dump($data);exit;
}

是可以成功的
string(9) "key1value"
但是当我访问其他页面的时候就会报：

CException

Please ensure that CRedisCache is installed and instantiatable.
/alidata/www/yii1/dev/protected/views/layouts/main.php(35)

23 <div class="container" id="page">
24 
25     <div id="header">
26         <div id="logo"><?php echo CHtml::encode(Yii::app()->name); ?></div>
27     </div><!-- header -->
28 
29     <div id="mainmenu">
30         <?php $this->widget('zii.widgets.CMenu',array(
31             'items'=>array(
32                 array('label'=>'Home', 'url'=>array('/site/index')),
33                 array('label'=>'About', 'url'=>array('/site/page', 'view'=>'about')),
34                 array('label'=>'Contact', 'url'=>array('/site/contact')),
35                 array('label'=>'Login', 'url'=>array('/site/login'), 'visible'=>Yii::app()->user->isGuest),
36                 array('label'=>'Logout ('.Yii::app()->user->name.')', 'url'=>array('/site/logout'), 'visible'=>!Yii::app()->user->isGuest)
37             ),
38         )); ?>
39     </div><!-- mainmenu -->
40     <?php if(isset($this->breadcrumbs)):?>
41         <?php $this->widget('zii.widgets.CBreadcrumbs', array(
42             'links'=>$this->breadcrumbs,
43         )); ?><!-- breadcrumbs -->
44     <?php endif?>
45 
46     <?php echo $content; ?>
47 

Stack Trace
#0	
+  /alidata/www/yii1/framework/base/CModule.php(394): PRedisCacheHttpSession->init()
#1	
+  /alidata/www/yii1/framework/web/CWebApplication.php(201): CModule->getComponent("session")
#2	
+  /alidata/www/yii1/framework/web/auth/CWebUser.php(199): CWebApplication->getSession()
#3	
+  /alidata/www/yii1/framework/base/CModule.php(394): CWebUser->init()
#4	
+  /alidata/www/yii1/framework/base/CModule.php(103): CModule->getComponent("user")
#5	
–  /alidata/www/yii1/dev/protected/views/layouts/main.php(35): CModule->__get("user")
30         <?php $this->widget('zii.widgets.CMenu',array(
31             'items'=>array(
32                 array('label'=>'Home', 'url'=>array('/site/index')),
33                 array('label'=>'About', 'url'=>array('/site/page', 'view'=>'about')),
34                 array('label'=>'Contact', 'url'=>array('/site/contact')),
35                 array('label'=>'Login', 'url'=>array('/site/login'), 'visible'=>Yii::app()->user->isGuest),
36                 array('label'=>'Logout ('.Yii::app()->user->name.')', 'url'=>array('/site/logout'), 'visible'=>!Yii::app()->user->isGuest)
37             ),
38         )); ?>
39     </div><!-- mainmenu -->
40     <?php if(isset($this->breadcrumbs)):?>
………………………………

这个错误，不知道是什么原因