i installed the 1.4B7 and 1.4B8 easily.
what u need to check :
- the user that connect to mysql database : same in all cfg files ? password ok ? it has the rights to the nagios db ?
- are you using or socket ? be sure the ports used arent blocked ( port to mysl serveur by example)
- check ndo2db.cfg ,nagios.cfg and ndomod.cfg. Be sure informations are same (same communication mode, same users and passwd, same db name etc )
- check your line command in nagios.cfg for the event broker
it's usually a mismatch between the cfg files and/or a problem with the mysql nagios db.