Resource property is empty in Room mailbox , where Room was added as Resources with other Rooms

HI ,

I am trying to read Resource property using delegate account having calendar Delegate access ,  i am able to access these on different servers (Exchange  2007_sp1 & Exchange 2010 sp1) on QA server its comming as empty . Code i am using is as follows ,

Object allAttendees = null;
 ExtendedPropertyDefinition prop = new ExtendedPropertyDefinition(DefaultExtendedPropertySet.Appointment, 0x8238, MapiPropertyType.String);
 appointment.TryGetProperty(prop, out allAttendees);

please help me find the answer or if someone can suggest better approach then please please tell me , that would be great help

Thanks in advance

THIS IS VERY URGENT

Dheeraj Kumar

Thank you Dheeraj Kumar