Could not read object configuration and apache


After installing nagios 2.7 when i access via web it shows the message "Could not read object configuration"
I’ve read a lot of forums and the nagios FAQ and done all…but nothing

Seeing the log i checked that nagios is doing the job (collecting information from the hosts and services) but the webpage doesn’t show them

I tried to change the perms and owner for the cgi and conf files with the same result

What can i do? I’m almost sure it has to do with apache and perms…but…maybe i’m wrong

Thankyou very much