Index: calendar-tool/tool/src/java/org/sakaiproject/calendar/tool/CalendarAction.java
===================================================================
--- calendar-tool/tool/src/java/org/sakaiproject/calendar/tool/CalendarAction.java	(revision 52336)
+++ calendar-tool/tool/src/java/org/sakaiproject/calendar/tool/CalendarAction.java	(working copy)
@@ -2214,7 +2214,13 @@
 				// form a reference to the default calendar for this request's site
 				calendarReference = CalendarService.calendarReference(ToolManager.getCurrentPlacement().getContext(), SiteService.MAIN_CONTAINER);
 				state.setPrimaryCalendarReference(calendarReference);
+			} 
+			else if (calendarReference.indexOf('/') == -1) 
+			{ // check if the value contains a / and is a full reference
+			    // if not, create a reference with the reference as id.
+			    calendarReference = CalendarService.calendarReference(ToolManager.getCurrentPlacement().getContext(), calendarReference);
 			}
+			state.setPrimaryCalendarReference(calendarReference);
 		}
 	}