Problem with rubberband not found on postbacks/ajax actions

			                        <td>
					                    <input id="ButtonCrop" onclick="Crop();" type="image" src="Images\ImageEditor\crop.jpg" /> &nbsp;
					                    <input id="ButtonRotateRight" onclick="RotateRight();" type="image" src="Images\ImageEditor\right.jpg" /> &nbsp;
					                    <input id="ButtonRotateLeft" onclick="RotateLeft();" type="image" src="Images\ImageEditor\left.jpg" /> &nbsp;
					                    <input id="ButtonBrightnessUp" onclick="BrightnessUp();" type="image" src="Images\ImageEditor\light.jpg" /> &nbsp;
					                    <input id="ButtonBrightnessDown" onclick="BrightnessDown();" type="image" src="Images\ImageEditor\dark.jpg" />
			                        </td>
		                        </tr>
			                    <tr>
				                    <td valign="top">
					                    <aur:BitmapViewer ID="viewer" runat="server" Width="344px" Height="270px" ImageLoadMode="AdaptiveTile" Rubberband="RectangleRubberband1"
						                    ZoomMode="BestFitShrinkOnly" ViewportAlignment="CenterCenter" BorderWidth="2" BorderStyle="Inset" ScrollBarsStyle="Auto" BackColor="White"> 
					                    </aur:BitmapViewer>
				                    </td>
				                    <td>
					                    &nbsp;
				                    </td>
				                    <td valign="top" width="100">
					                    <span id="SpanWarning" style="display: none; font-weight: bold; color: red">Selected
						                    area is too small to get good quality of prints. </span>
					                    <asp:CustomValidator ID="imageValidation" runat="server"></asp:CustomValidator>
				                    </td>
				                    <td>
				                        <asp:Button ID="OK" runat="server" OnCommand="UploadImage" Text="Gem" />
				                    </td>
			                    </tr>
		                    </table>
		                    <aur:RectangleRubberband ID="RectangleRubberband1" runat="server" ResizeMode="Proportional" GripsVisible="True" MaskVisible="True" />
		                    <script type="text/javascript">
			                    Sys.Application.add_load(Application_load);
		                    </script>

function Crop(){
	if (viewer.get_status() != GraphicsMill.UpdateStatus.busy) {
		//Process cropping via remote scripting
		var r = rectangleRubberband.get_rectangle();
		if (r.width < 1 || r.height < 1) {
			return;
		}
	
		viewer.invokeRemoteMethod("Crop", [r.x, r.y, r.width, r.height]);	

		updateRectangle=true;
	}
	else {
		alert("Please wait until previous operation will be completed.");
	}
}