Hi - i've got a problem in exporting an image. It used to work but now all I get is the background and no events

my codee is

protected void ButtonExport_Click(object sender, EventArgs e)
{
// int hourHeight = DayPilotCalendar1.CellDuration * DayPilotCalendar1.CellHeight;
// int hourHeight = DayPilotCalendar1.CellsPerHour * DayPilotCalendar1.CellHeight;
int hourHeight = DayPilotCalendar1.CellDuration * DayPilotCalendar1.CellHeight;
// DayPilotCalendar1.HeightSpec = HeightSpecEnum.BusinessHours; //this sets the printable area - nice___
DayPilotCalendar1.HeightSpec = HeightSpecEnum.Full; //this sets the printable area - nice___

Response.Clear();
Response.ContentType = "image/png";
Response.AddHeader("content-disposition", "attachment;filename=PrintSchedule" + DateTime.Now + ".png");
MemoryStream img = DayPilotCalendar1.Export(ImageFormat.Png, 9 * hourHeight);
// MemoryStream img = DayPilotCalendar1.Export(ImageFormat.Png, 9 * 10);
img.WriteTo(Response.OutputStream);
Response.End();

}

Any ideas?
Thanks LL