Hibernate 4 lazy loading doesn't work

I am working on a web application using spring 3 and hibernate 4. I am having trouble lazy-loading a set of granted permissions of a group to which a user belongs. When a user object is retrieved from the database, its Group object doesn't have any permissions even though user.getGroup().getPermissions() is invoked explicitly.

I noticed that in debug mode, if I mouse-over the User object and then navigate to the Group object inside the User object, and then navigate to its permissions, I can see its type is shown as PersistentSet, and expanding it will load permissions properly. But in non-debug mode, permissions are never lazy-loaded. What am I missing here? Thanks in advance.

Here are the relationships among the entities: Users have an one-to-many relationship with groups, and groups have a many-to-many relationship with permissions.

Here's the definition of the UserDaoImpl class

@Repository
@Transactional
public class UserDaoImpl implements UserDao  {

    @Autowired
    private SessionFactory sessionFactory;

    private Session getSession() {
        return sessionFactory.getCurrentSession();
    }

    @Override
    public User get(String username) {
        Session session = getSession();
        User user = (User) session.createCriteria(User.class).add(Restrictions.eq("username", username)).uniqueResult();

        Group g = user.getGroup();

        // calling g.getGrantedPermissions() doesn't load any permission
        Set<Permission> permissions = g.getGrantedPermissions();
        return user;
    }
}

Here's the definition of the Permission class

@Entity
public class Permission {
    @Id
    @GeneratedValue
    private Long id;

    @Column
    private String name;

    @Column
    private String description;

    public Permission()
    {

    }

    public Long getId() {
        return id;
    }

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

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    public String getName() {
        return name;
    }

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

Here's the definition of the Group class

@Entity
@Table(name="\"Group\"")
public class Group {
    public static final String ROLE_VALID_USER = "ROLE_VALID_USER";

    @Id
    @GeneratedValue
    private Long id;

    @Column
    private String description;

    @Column
    private String role;

    @ManyToMany
    @JoinTable(name = "granted_permission", 
            joinColumns = {@JoinColumn(name = "GROUP_ID", nullable = false, updatable = false) }, 
            inverseJoinColumns = { @JoinColumn(name = "PERMISSION_ID", nullable = false, updatable = false) })
    private Set<Permission> grantedPermissions;

    public Group()
    {

    }

    public Long getId() {
        return id;
    }

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

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    public String getRole() {
        return role;
    }

    public void setRole(String role) {
        this.role = role;
    }

    public Set<Permission> getGrantedPermissions() {
        return grantedPermissions;
    }

    public void setGrantedPermissions(Set<Permission> grantedPermissions) {
        this.grantedPermissions = grantedPermissions;
    }
}

Here's the definition of the User class

@Entity
public class User {
    @Id
    @Column(name="USERNAME")
    private String username;

    @Column(name="PASSWORD")
    private String password;

    @Transient
    private final boolean enabled = true;

    @Column
    private String name;

    @Column(name="EMAIL")
    private String email;

    @Column(name="PHONE")
    private String phone;

    @ManyToOne
    private Group group;

    @ManyToOne
    @JoinColumn(name="ORIGINAL_BRANCH_ID")
    private Branch originalBranch;

    @ManyToOne
    @JoinColumn(name="ID_OF_RESPONSIBLE_BRANCH")
    private Branch responsibleBranch;

    public User()
    {

    }

    public String getUsername() {
        return username;
    }

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

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getRole() {
        return group.getRole();
    }

    public boolean isEnabled() {
        return enabled;
    }

    public String getName() {
        return name;
    }

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

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getPhone() {
        return phone;
    }

    public void setPhone(String phone) {
        this.phone = phone;
    }

    public Group getGroup() {
        return group;
    }

    public void setGroup(Group group) {
        this.group = group;
    }

    public Branch getOriginalBranch() {
        return originalBranch;
    }

    public void setOriginalBranch(Branch originalBranch) {
        this.originalBranch = originalBranch;
    }

    public Branch getResponsibleBranch() {
        return responsibleBranch;
    }

    public void setResponsibleBranch(Branch responsibleBranch) {
        this.responsibleBranch = responsibleBranch;
    }
}

Here's the persistence configuration:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   xmlns:context="http://www.springframework.org/schema/context"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xsi:schemaLocation="http://www.springframework.org/schema/beans 
                           http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
                           http://www.springframework.org/schema/tx 
                           http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
                           http://www.springframework.org/schema/context 
                           http://www.springframework.org/schema/context/spring-context-3.0.xsd">

       <tx:annotation-driven />

       <context:annotation-config />

    <bean id="transactionManager"
        class="org.springframework.orm.hibernate4.HibernateTransactionManager">
        <property name="sessionFactory" ref="sessionFactory" />
    </bean>

    <context:component-scan base-package="net.acme.prs" />

    <bean id="sessionFactory" class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
        <property name="dataSource" ref="mysqlDataSource" />
        <property name="packagesToScan" value="net.acme.prs" />
        <property name="hibernateProperties">
            <props>
                <prop key="hibernate.dialect">
                    org.hibernate.dialect.MySQL5InnoDBDialect
                </prop>
                <prop key="hibernate.show_sql">false</prop>
            </props>
        </property>
    </bean>

    <bean id="mysqlDataSource" class="org.apache.commons.dbcp.BasicDataSource"  destroy-method="close">
        <property name="driverClassName" value="com.mysql.jdbc.Driver" />
        <property name="url" value="jdbc:mysql://localhost:3306/prs" />
        <property name="username" value="" />
        <property name="password" value="" />
    </bean>
</beans>