Gridview inside modal popup extender disturb ajax calender extender

Hi,

I am using Ajax Modal popup extender to shows interactive message for the user. I am using 3 model popup extender for different type of message. 

I am using gridview inside one of the model popup extender. Then its distube ajax calender extender control in my webpage. When user click on textbox which is extended to calender its appear top left corner of the page.

I am just troubleshooting the page and figure out if i just remove the gridview which i used inside the model popup extender then calander extender display at its correct location. 

I dont know why its happend. any solution here is my aspx.

<asp:UpdatePanel ID="UpdatePanel1" runat="server"><ContentTemplate><!-- Warning Message--><div><asp:ModalPopupExtender ID="ModalPopupExtender1" BackgroundCssClass="ModalPopupBG"
                        runat="server" OkControlID="btnOkay" TargetControlID="lbmsgError" PopupControlID="Panel1"
                        Drag="true" PopupDragHandleControlID="PopupHeader"></asp:ModalPopupExtender><div id="Panel1" style="display: none;" class="popupConfirmation"><div class="popup_Container"><div class="popup_Titlebar" id="PopupHeader"><asp:Label ID="lbmsgHeader" runat="server" Text="Error"></asp:Label></div><div class="popup_Body"><p><asp:Label ID="lbmsgError" runat="server" Text=""></asp:Label></p></div><div class="popup_Buttons"><input id="btnOkay" value="Stänga" type="button" /></div></div></div></div><!-- Room Rent History --><div><asp:ModalPopupExtender ID="ModalPopupExtender2" BackgroundCssClass="ModalPopupBG"
                        runat="server" OkControlID="Button1" TargetControlID="Label3" PopupControlID="Div1"
                        Drag="true" PopupDragHandleControlID="Div2"></asp:ModalPopupExtender><div id="Div1" style="display: none; width: 700px;" class="popupConfirmation"><div class="popup_Container"><div class="popup_Titlebar" id="Div2"><asp:Label ID="Label2" runat="server" Text="Hyra History"></asp:Label></div><div class="popup_Body"><p><%--<asp:GridView ID="gvHyraHistory" runat="server" CssClass="mGrid"></asp:GridView>--%><asp:Label ID="Label3" runat="server" Text="Label"></asp:Label></p></div><div class="popup_Buttons"><caption><input id="Button1" value="Stänga" type="button" /></caption></div></div></div></div><!-- Save Message--><div><asp:ModalPopupExtender ID="ModalPopupExtender3" BackgroundCssClass="ModalPopupBG"
                        runat="server" OkControlID="btnSaveMessage" TargetControlID="lbSaveMessage" PopupControlID="Div3"
                        Drag="true" PopupDragHandleControlID="Div4"></asp:ModalPopupExtender><div id="Div3" style="display: none;" class="popupConfirmation"><div class="popup_Container"><div class="popup_Titlebar" id="Div4"><asp:Label ID="lbSaveMessageHeader" runat="server" Text=""></asp:Label></div><div class="popup_Body"><caption><p><asp:Label ID="lbSaveMessage" runat="server" Text=""></asp:Label></p></caption></div><div class="popup_Buttons"><caption><input id="btnSaveMessage" value="Stänga" type="button" /></caption></div></div></div></div></ContentTemplate></asp:UpdatePanel>