Ansonsten hier noch ein Text aus dem Redbook "Lotus Notes and Domino 7 Enterprise Upgrade Best Practices":
Delete the existing file BUSYTIME.NSF (or CLUBUSY.NSF in a clustered environment).
Domino 7 uses a dedicated server task to maintain information for the Rooms and
Resource database.
Important: The Rooms and Resources Manager (RnRMgr) works only if the Rooms
and Resources database has been created using the RESRC7.NTF template. If you do
not delete the previous database, upgrade your Rooms and Resources database using
the RESRC7.NTF template.
You must add the task RnRMgr in the line ServerTasks to the server NOTES.INI file:
ServerTasks=Update,Replica,Router,AMgr,AdminP,CalConn,Sched,HTTP, RnRMgr
Alternatively, you can create a program document to load this task at server startup.