After deleting a widget on a zone, widgets can't be dropped on this zone anymore

What steps will reproduce the problem?
1. Add 1 or more widgets on several zones
2. Delete a widget from a zone
3. Try to drag a widget from an other zone and drop it into the one where 
you deleted a widget

What is the expected output? What do you see instead?
I expect to have the possibility to move widgets from a zone to an other, 
even if I previously deleted a widget on this zone before.

What version of the product are you using? On what operating system?
Version 2.4 on WinXP SP3

Please provide any additional information below.
I think that the zone is not properly refreshed after the deletion of a 
widget.
I saw this code in WidgetInstanceZone.ascx.cs :

    private void RefreshZoneUpdatePanel()
    {
        this.WidgetZoneUpdatePanel.Update();

//ScriptManager.RegisterStartupScript(this.WidgetHolderPanelTrigger, 
this.WidgetHolderPanelTrigger.GetType(), this.ClientID + "_InitWidgets" + 
DateTime.Now.Ticks.ToString(),
        //        "$(document).ready(function() {" + 
"DropthingsUI.refreshSortable('{0}');"
        //        .FormatWith(this.WidgetPanel.ClientID) + "});", true);
    }

but refreshSortable doesn't exist anymore.
I saw Issues 12 and tried to fix this bug by following that way, but I 
couldn't.

Original issue reported on code.google.com by nourdine...@gmail.com on 11 Feb 2010 at 4:30

AntonioChiancone / dropthings

After deleting a widget on a zone, widgets can't be dropped on this zone anymore #59