you may debbug your ospf configuration with the following commands
FortiOS 4.0
Forti# diagnose ip router ospf all enable
Forti# diagnose ip router ospf level info
other options are below
critical critical level
error error level
info information level
none none level
warn warning level
Forti# diagnose debug enable
to cancel the output just run “diagnose debug disable” while output flows on your screen.