null in maps are handled inconsistently --------------------------------------- Key: HHH-772 URL: http://opensource.atlassian.com/projects/hibernate/browse/HHH-772 Project: Hibernate Core Issue Type: Improvement Components: core Reporter: Max Rydahl Andersen Fix For: 3.1 beta 1 regarding case 00004729. group.getUsers().put("something", null); Does not result in any insert. Inserting "something", null manually into the underlying table and when hibernate reads the map will have "something"->null in the map.