AJAX :: Hover Extender Not Working After Postback

I bind a hover extender to a cell in a gridview, using following code:

Sub GridView1_RowDataBound(ByVal sender
As
Object,
ByVal e
As System.Web.UI.WebControls.GridViewRowEventArgs)
Handles GridView1.RowDataBound
If e.Row.RowType = DataControlRowType.DataRow
Then
Dim hoverMenu
As HoverMenuExtender =
CType(e.Row.FindControl("hoverMenu"), HoverMenuExtender)
e.Row.Cells(1).Controls.Item(0).ID = e.Row.RowIndex.ToString()
hoverMenu.TargetControlID = e.Row.Cells(1).Controls.Item(0).ID
End
If
End
Sub

Now This works perfectly and the panel appear when hovering over the second cell. However after a postback it is no longer working and no panel will show when hovering over the cell.