hibernate insert

异常:
Hibernate: 
    /* insert com.njusc.knowledge.model.CustomTypeModel
        */ insert 
        into
            CustomType_Tab
            (typeName, userId, insertTime, updateTime, delFlag, parent_id, id) 
        values
            (?, ?, ?, ?, ?, ?, ?)
2008-12-11 10:00:25,497 [http-8080-Processor23] WARN  org.hibernate.util.JDBCExceptionReporter - SQL Error: 547, SQLState: 23000
2008-12-11 10:00:25,497 [http-8080-Processor23] ERROR org.hibernate.util.JDBCExceptionReporter - INSERT 语句与 COLUMN FOREIGN KEY SAME TABLE 约束 'FKF3E693A1EFE3A3C7' 冲突。该冲突发生于数据库 'glj_zsk'，表 'CustomType_Tab', column 'id'。
2008-12-11 10:00:25,497 [http-8080-Processor23] ERROR org.hibernate.event.def.AbstractFlushingEventListener - Could not synchronize database state with session
org.hibernate.exception.ConstraintViolationException: could not insert: [com.njusc.knowledge.model.CustomTypeModel]

Caused by: java.sql.SQLException: INSERT 语句与 COLUMN FOREIGN KEY SAME TABLE 约束 'FKF3E693A1EFE3A3C7' 冲突。该冲突发生于数据库 'glj_zsk'，表 'CustomType_Tab', column 'id'。

配置文件: <class name="CustomTypeModel" table="CustomType_Tab" lazy="true">
<id name="id" type="string" unsaved-value="null" length="32">
<column name="id" not-null="true" length="32" />
<generator class="uuid.hex" />
</id>
<property name="typeName" length="100"/>
<property name="userId" length="32"/> 
<property name="insertTime"/>
<property name="updateTime"/>
<property name="delFlag"/> 
<many-to-one name="parent" column="parent_id"></many-to-one>
<bag name="children" inverse="true" lazy="true" where="delFlag=1">
<key column="parent_id"></key>
<one-to-many class="CustomTypeModel" not-found="ignore" />
</bag>
</class>请高手解答