have you ever tried to install bulk importer on alfresco 5.0 ? i didn't found something on this topic and when i'm trying to install latest bulk from code.google.com/p/alfresco-bulk-filesystem-import it doesn't work because of compatibility
in case you didn't notice, a version of the bulk importer was added a while ago into the out-of-the-box alfresco, you can find it in your server at /alfresco/service/bulkfsimport on the other hand, if you already knew, but you still want to use that tool I'm afraid I can't help you.