I am using PostgreSQL which utilizes sequence generator. Declaring id | @Id | @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "hibernate3_sequence") | private Long id; | Wiring up sequence generator for all entities in orm.xml | <entity-mappings | xmlns="http://java.sun.com/xml/ns/persistence/orm" | xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" | xsi:schemaLocation="http://java.sun.com/xml/ns/persistence/orm orm_1_0.xsd" | version="1.0"> | <sequence-generator | name="hibernate3_sequence" | sequence-name="postmaster_sequence" /> | </entity-mappings> | Works like a charm. Have you tried all available options for SequenceGenerator annotation? | @Target({TYPE, METHOD, FIELD}) @Retention(RUNTIME) | public @interface SequenceGenerator { | String name(); | String sequenceName() default ""; | int initialValue() default 1; | int allocationSize() default 50; | } | Yet, like I said, I am using PostgreSQL 7.4. Your problem could be DB related. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3961261#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...