I'm not sure if this is a bug, but it appears that kSpam is only monitoring email for one domain hosted on our domino server. We have about 15 domains. Some 3 are running as hosted organizations, the others are simply mapped to an organization via an SMTP Inbound Site document.
When mail arrives for the primary domain, mail is added to mailgood.nsf database. Any mail arriving to any other domain is ignored, including domains in hosted organizations.