How can I make an AJAXToolkit Modal popup redisplay and the contents rebind after postback

Question

I have a modal popup extender that pops up another user control with a FormView. When I save the form in edit mode if there are errors I wish to redisplay the dialog with the error summary and the form still in edit mode. What happens now is I get the popup to comeback up but it's in ReadOnly mode. Here is an example of the code that I'm using when I first show the dialog and when I post back and there are errors.

ListViewEdit.ItemId = (int)ListView.SelectedDataKey["CustomerID"];
ListViewEdit.Mode = FormViewMode.Edit;
ListViewEdit.DataBind();
mdlPopup.Show();

Any help would be greatly appreciated.