SecondaryTable problem

[osganian]

Hi I'm using JBoss 4.0.3SP1 and I have an entity bean that stores its data in 2 tables that are joined by an id. My class looks like:

@Entity(access=AccessType.PROPERTY)
@Table(name="users1")
@SecondaryTable(name="users2",
 join={@JoinColumn(name="id",
 referencedColumnName="user_id")})
public class User implements Serializable {
 int id;
 String username = null;
 String firstName = null;

 @Id(generate=GeneratorType.AUTO)
 @Column(name="user_id")
 public int getId() {
 return id;
 }

 public void setId(int id) {
 this.id = id;
 }

 @Column(nullable=false,length=50)
 public String getUsername() {
 return super.getUsername();
 }

 public void setUsername(String name) {
 this.username = name;
 }

 @Column(name="firstName", secondaryTable="users2")
 public String getFirstName() {
 return firstName;
 }

 public void setFirstName(String firstName) {
 this.firstName = firstName;
 }
}

But I get the following exception when I run:

java.sql.SQLException: Unknown column 'firstName' in 'field list'
 at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2928)
 at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1571)
 at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1666)
 at com.mysql.jdbc.Connection.execSQL(Connection.java:2994)
 at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:936)
 at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:1166)
 at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:1082)
 at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:1067)
 at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2064)

What am I missing?

Any help would be great!
Mike