How SystemStarter Handles Duplicate Services

Once a service is provided no other startup item bundles providing that service will be executed, even if they provide other unique services. When two or more startup item bundles provide the same service, SystemStarter will give priority to bundles residing in the /Library/StartupItems directory. If such an item succeeds, all other items providing that service will be ignored, as stated above. However, if the item fails to provide that service, the next item will get a chance, etc., until the service is successfully provided. (See the Search Paths for Startup Items section for details on the search order.)