Forms Data Controls :: Cannot Access The Non Visible Columns Values

I've created a gridview having an Id column whose visible property is set to false, because I don't want users to see that column. Now when user clicks on the edit button in a particular row I want to fetch the id of the cell in the Id column of that particular row. So, for that purpose I used -

void GridView_RowEditing(object sender, GridViewEditEventArgs e)
{
string Id = GridView.Rows[e.NewEditIndex].Cells[0].Text;
}

In the above code, Cells 0th index is the column index whose visible property is kept false. Now the problem I face here is that if the columns visible property is true then I can easily fetch the contents of that particular cell with the above code. But, in invisible mode I get only "" value i.e. I don't get the text or the content of that cell. Why does it happen? I don't face this problem with DataGrid Control used with 1.0 and 1.1 version. And how to resolve it or in this case is there another way of fetching the content of the invisible cell?