Problem in implementing lazy loading in MTable from Viritin addon

Hello guys,

I'm using Varitin addon (v 1.61) in my web app. I'm trying to implement lazy loading using MTable as following:

private List<UserAccount> users = new ArrayList<UserAccount>();
users = gbemForCommonDb.getEntitymanager().createQuery("SELECT ua FROM UserAccount ua")
                                   .getResultList();

usersMTable = new MTable(CommonUserAccount.class)
                            .withFullHeight()
                            .withFullWidth()
                            .withStyleName("striped", ValoTheme.TABLE_BORDERLESS, ValoTheme.TABLE_NO_HORIZONTAL_LINES, ValoTheme.TABLE_NO_VERTICAL_LINES)
                            .withProperties("email", "firstname", "lastname", "username")
                            .withColumnHeaders(GroupBuilderApp.getInstance().getTranslation("email"),
                                               GroupBuilderApp.getInstance().getTranslation("firstname"), 
                                               GroupBuilderApp.getInstance().getTranslation("lastname"),
                                               GroupBuilderApp.getInstance().getTranslation("username"))
                            .withValueChangeListener(new MValueChangeListener() {

            @Override
            public void valueChange(MValueChangeEvent event) {
                setModificationsEnabled(event.getProperty().getValue() != null);
            }

            private void setModificationsEnabled(boolean b) {
                 editItem.setEnabled(b);
                 removeItem.setEnabled(b);
            }
        }).lazyLoadFrom(new LazyList.PagingProvider() {

            @Override
            public List findEntities(int firstRow) {
                return users.subList(firstRow, 20);
            }
        }, new LazyList.CountProvider() {

            @Override
            public int size() {
                return users.size();
            }
        });​
        usersMTable.addBeans(users);

But getting the following error in the line usersMTable.addBeans(users) :

Severe:   java.lang.UnsupportedOperationException
    at java.util.AbstractList.add(AbstractList.java:148)
    at java.util.AbstractList.add(AbstractList.java:108)
    at org.vaadin.viritin.ListContainer.addItem(ListContainer.java:378)

Am I doing anything wrong? If so then what is the solution then?
@MattiTahvonen it would be a great pleasure for me if you have a look on my issue :)
Thanks in advance :)