I am trying to rewrite Grid in Magento Admin for Newsletter Subscribers. I am using code below to rewrite Grid in Custom module:

config.php

<global>    
    <blocks>
        <custommodule>
            <class>Namespace_Module_Block</class>
        </custommodule>
        <adminhtml>
            <rewrite>
                <!-- Extra column in newsletter subscribers grid  -->
                <newsletter_subscriber_grid>Namespace_Module_Block_Adminhtml_Newsletter_Subscriber_Grid</newsletter_subscriber_grid>
            </rewrite>
        </adminhtml>
        <catalog>
            <rewrite>
                <product_list_toolbar>Namespace_Module_Block_Product_List_Toolbar</product_list_toolbar>
                <product_view>Namespace_Module_Block_Product_View</product_view>
            </rewrite>
        </catalog>
    </blocks>
<global>

Namespace_Module_Block_Adminhtml_Newsletter_Subscriber_Grid

    <?php
    class Namespace_Module_Block_Adminhtml_Newsletter_Subscriber_Grid extends Mage_Adminhtml_Block_Newsletter_Subscriber_Grid 
    {
        protected function _prepareColumns()
        {
            // extra grid column added
        }
    }

But Grid is not updating in Admin... Anything wrong I am doing here...??

I am trying to rewrite Grid in Magento Admin for Newsletter Subscribers. I am using code below to rewrite Grid in Custom module:

config.xml (only required part is added)

<global>    
    <blocks>
        <custommodule>
            <class>Namespace_Module_Block</class>
        </custommodule>
        <adminhtml>
            <rewrite>
                <!-- Extra column in newsletter subscribers grid  -->
                <newsletter_subscriber_grid>Namespace_Module_Block_Adminhtml_Newsletter_Subscriber_Grid</newsletter_subscriber_grid>
            </rewrite>
        </adminhtml>
        <catalog>
            <rewrite>
                <product_list_toolbar>Namespace_Module_Block_Product_List_Toolbar</product_list_toolbar>
                <product_view>Namespace_Module_Block_Product_View</product_view>
            </rewrite>
        </catalog>
    </blocks>
<global>

Namespace_Module_Block_Adminhtml_Newsletter_Subscriber_Grid

    <?php
    class Namespace_Module_Block_Adminhtml_Newsletter_Subscriber_Grid extends Mage_Adminhtml_Block_Newsletter_Subscriber_Grid 
    {
        protected function _prepareColumns()
        {
            // extra grid column added
        }
    }

But Grid is not updating in Admin... Anything wrong I am doing here...??

I am trying to rewrite Grid in Magento Admin for Newsletter Subscribers. I am using code below to rewrite Grid in Custom module:

config.php

<global>    
    <blocks>
        <custommodule>
            <class>Namespace_Module_Block</class>
        </custommodule>
        <adminhtml>
            <rewrite>
                <!-- Extra column in newsletter subscribers grid  -->
                <newsletter_subscriber_grid>Namespace_Module_Block_Adminhtml_Newsletter_Subscriber_Grid</newsletter_subscriber_grid>
            </rewrite>
        </adminhtml>
        <catalog>
            <rewrite>
                <product_list_toolbar>Namespace_Module_Block_Product_List_Toolbar</product_list_toolbar>
                <product_view>Namespace_Module_Block_Product_View</product_view>
            </rewrite>
        </catalog>
    </blocks>
<global>

Namespace_Module_Block_Adminhtml_Newsletter_Subscriber_Grid

    <?php
    class Namespace_Module_Block_Adminhtml_Newsletter_Subscriber_Grid extends Mage_Adminhtml_Block_Newsletter_Subscriber_Grid 
    {
        protected function _prepareColumns()
        {
            // extra grid column added
        }
    }

But Grid is not updating in Admin... Anything wrong I am doing here...??

I am trying to rewrite Grid in Magento Admin for Newsletter Subscribers. I am using code below to rewrite Grid in Custom module:

config.php

<global>    
    <blocks>
        <custommodule>
            <class>Namespace_Module_Block</class>
        </custommodule>
        <adminhtml>
            <rewrite>
                <!-- Extra column in newsletter subscribers grid  -->
                <newsletter_subscriber_grid>Namespace_Module_Block_Adminhtml_Newsletter_Subscriber_Grid</newsletter_subscriber_grid>
            </rewrite>
        </adminhtml>
        <catalog>
            <rewrite>
                <product_list_toolbar>Namespace_Module_Block_Product_List_Toolbar</product_list_toolbar>
                <product_view>Namespace_Module_Block_Product_View</product_view>
            </rewrite>
        </catalog>
    </blocks>
<global>

Namespace_Module_Block_Adminhtml_Newsletter_Subscriber_Grid

    <?php
    class Namespace_Module_Block_Adminhtml_Newsletter_Subscriber_Grid extends Mage_Adminhtml_Block_Newsletter_Subscriber_Grid 
    {
        protected function _prepareColumns()
        {
            // extra grid column added
        }
    }

But Grid is not updating in Admin... Anything wrong I am doing here...??