Mage Register is Cleared by Grid Search Button No Page Reload

Question

Even though there is no page reload, and grid ajax is set to true, the Mage::registry gets cleared when the grid search button is clicked.

I am using a registry variable related to an option type in the grid.

Is there a way to avoid the registry getting cleared in this scenario?

class MyModule_Block_Adminhtml_MyGrid extends Mage_Adminhtml_Block_Widget_Grid
{

        public function __construct()
        {
            parent::__construct();
            $this->setTemplate('mymodule/mymodel/meter/grid.phtml');
            $this->setId('time_settings');
            $this->setDefaultSort('sort_order');
            $this->setDefaultDir('ASC');
            $this->setSaveParametersInSession(true);
            $this->setUseAjax(true);
        }
        ....
        public function getGridUrl()
        {
            return $this->getUrl('*/*/metergrid', array('_current'=>true));
        }

Answer 1

registry does not mean session.
A value placed in registry acts somehow as a global variable. It is available everywhere in the current request.
An AJAX call is a totally different request.
If you need some value from the initial request in your ajax call you should store that value in session.