Hi, When I change the days view by calling: dpc1.refreshCallBack(null,1); and then dpc1.refreshCallBack(null,5); I get a JS Error in prepareEvents(): $P.parentNode.removeChild($P); "parentNode is null" This didn't happens only in ver 5.6.1808 and didn't happen in 5.5.1780 I'm using IE6 (didn't happen in FF) didn't check in IE7 I used the demo code: protected void DayPilotCalendar1_Refresh(object sender, RefreshEventArgs e) { DayPilotCalendar1.StartDate = e.StartDate; DayPilotCalendar1.Days = e.Days; DataTable table = GetData(); DayPilotCalendar1.DataSource = table; DayPilotCalendar1.DataBind(); DayPilotCalendar1.Update(CallBackUpdateType.Full); } public DataTable GetData() { DataTable dt; dt = new DataTable(); dt.Columns.Add("start", typeof(DateTime)); dt.Columns.Add("end", typeof(DateTime)); dt.Columns.Add("name", typeof(string)); dt.Columns.Add("id", typeof(string)); dt.Columns.Add("column", typeof(string)); dt.Columns.Add("allday", typeof(bool)); DataRow dr; dr = dt.NewRow(); dr["id"] = 2; dr["start"] = Convert.ToDateTime("16:00"); dr["end"] = Convert.ToDateTime("17:00"); dr["name"] = "Event 2"; dr["column"] = "A"; dt.Rows.Add(dr); dt.PrimaryKey = new DataColumn[] { dt.Columns["id"] }; return dt; } Thanks