If you have ever run a Coracleanup against your database, please review this technical document. It's highly likely that because you ran Coracleanup, that you now have some orphaned discovered software records in your database.
The document provides steps to re-enable two database foreign key constraints that Coracleanup disables, but forgets to re-enable! It also provides a SQL query that will remove any discovered software that is unmatched with any registered computer in the database.
Database Cleanup: Orphaned Discovered Software Records caused by Coracleanup
Brian Fontana, CA Support