I'm not sure if this is a bug or design decision but I'm having problems with it. Therefore want to inform you.
My problem is following: I'm trying to load page in panel and want to pass parameters to this page. And doing that by adding them
to url. Something like that:

protected void WorkingTime_Click(object sender, AjaxEventArgs e)
            string url = "~/Secure/WorkingTime.aspx";
            String date = e.ExtraParams["selectedDate"];
            if (!String.IsNullOrEmpty(date))
                url += "?selectedDate=" + HttpUtility.UrlEncode(date);
            this.WorkingAreaPanel.Load(new LoadConfig(url, LoadMode.IFrame, true));
but I'm having poblems in WorkingTime.aspx when trying to read selected date parameter, becuase Coolite attaches this to the end of url:
                url = url + "?" + new Date().getTime();
so my date value from <date> comes to <date>?<new Date().getTime()>.
Plz see loadIFrame method in Ext.Panel.override in file coolite-core.js.