I don't know how to relate this bug to jboss please anyone relate this it's a very worst bug.

In Jboss 7.x or after versions like jboss eap 6.2.0 i found this bug,  @TransactionAttribute(TransactionAttributeType.SUPPORTS) at class level,

makes the container ignore a method declaration of @TransactionAttribute(TransactionAttributeType.REQUIRED) and throw  javax.persistence.TransactionRequiredException

Other way to avoid  javax.persistence.TransactionRequiredException in bugged versions of jboss is using a interface without generics

In jboss 6 versions @TransactionAttribute(TransactionAttributeType.SUPPORTS) at class level works as ejb-spec.

Example:

@Stateless
@Local(BO.class)
@TransactionManagement(TransactionManagementType.CONTAINER)
@TransactionAttribute(TransactionAttributeType.SUPPORTS)
public class BOImpl implements BO {
    @PersistenceContext(unitName = "sgenEjbTestPU")
    private EntityManager em;

    @Override
    @TransactionAttribute(TransactionAttributeType.REQUIRED)
    public AppParam saveOrUpdate(AppParam param) {
        em.persist(param);
        return param;
    }
}

import br.com.pegasus.sgen.domain.AppParam;
public interface BO extends BOIFGeneric<AppParam, Integer> {
}

public interface BOIFGeneric<T, Id> {
    T saveOrUpdate(T param);
}

import br.com.pegasus.sgen.domain.AppParam;
public interface BOIFWithoutGenerics {
    AppParam saveOrUpdate(AppParam param);
}

@Entity
@Table(name = "tb_app_param")
@XmlRootElement
public class AppParam implements Serializable {
    private static final long serialVersionUID = 4818981684503640410L;

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Basic(optional = false)
    @Column(name = "id_app_param")
    private Integer id;

    @Basic(optional = false)
    @Column(name = "name")
    private String name;

    @Basic(optional = false)
    @Column(name = "js_value")
     private String jsValue;

    public AppParam() {
    }

    public AppParam(Integer id) {
        this.id = id;
    }

    public AppParam(String name) {
        this.name = name;
    }

    public AppParam(Integer id, String name, String jsValue) {
        this.id = id;
        this.name = name;
        this.jsValue = jsValue;
    }

    public Integer getId() {
        return this.id;
    }

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

    public String getName() {
        return this.name;
    }

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

    public String getJsValue() {
        return this.jsValue;
    }

    public void setJsValue(String jsValue) {
        this.jsValue = jsValue;
    }

    public int hashCode() {
        int hash = 0;
        hash += (this.id != null ? this.id.hashCode() : 0);
        return hash;
    }

    public boolean equals(Object object) {
        if (!(object instanceof AppParam)) {
            return false;
        }
        AppParam other = (AppParam) object;
        if (((this.id == null) && (other.id != null)) || ((this.id != null) && (!this.id.equals(other.id)))) {
            return false;
        }
        return true;
    }

  }

in persistence.xml
<persistence-unit name="sgenEjbTestPU" transaction-type="JTA">
        <provider>org.hibernate.ejb.HibernatePersistence</provider>
        <jta-data-source>java:/sgenXAMysqlDS</jta-data-source>
        <jar-file>lib/sgen-domain-1.0.0.jar</jar-file>
        <properties>
            <property name="hibernate.show_sql" value="true" />
            <property name="hibernate.format_sql" value="true" />
            <property name="hibernate.use_sql_comments" value="false" />
            <property name="hibernate.dialect" value="org.hibernate.dialect.MySQLInnoDBDialect" />
        </properties>
</persistence-unit>

in com/mysql/main/modules.xml
<?xml version="1.0" encoding="UTF-8"?>
<module xmlns="urn:jboss:module:1.0" name="com.mysql">
  <resources>
    <resource-root path="mysql-connector-java-5.1.22-bin.jar"/>
  </resources>
  <dependencies>
    <module name="javax.api"/>
    <module name="javax.transaction.api"/>
  </dependencies>
</module>

About me i'm a SCJP 6, SCWD 5 and OCPBCD 5 and 6 years working with Java, this is not my code error, it's a bug of jboss.