Gridview PageIndexChanging issue

Hi,
I have a gridview which is not working when paging is enabled and handled in PageIndexChangeing event. Here is what I am doing.
protected void Page_Load(object sender, EventArgs e)         {                          BuildSocialEventTable();                   } private DataTable socialEvents;
        private void BuildSocialEventTable()         {               //all the connection to sql and dataset is filled here..                 DataSet ds = new DataSet();    ...