The event is added manually, by the "Quick Add" or by a 3rd-party app?
Anyway, Refresh Rainlendar2 is better than Restart it.
The New Event dialog has a dropdown list besides the alarm clock icon to change the calendar where you store the event. If you want to set as default you can use the Template menu in the same dialog window.
If the event is added by Quick Add, see www.rainlendar.net/cms/index.php?option=com_kunena&Itemid=42&func=view&id=14182&catid=3#14192
(Create a template and save it as "quickadd")