how to import localhost.cfg into oreon ?

[bluenight]

Hi, i'm using oreon and nagios, in my nagios i already configured hosts and services, n it is working perfectly with nagios web-interface,
now problem is wen i'm trying to import this localhost.cfg, hosts n services r added into oreon, it displays hosts, hostgroups, services in under configuration tab of oreon web-interface, but oreon is unable to monitor the hosts/services,
wen i check event log tab, it shows all events like which service is being checkd and problems of each n every hosts n services but it is unable to show up in services and hosts tabs.
can any1 please help me to solve dis ??