<?xml version="1.0" encoding="UTF-8"?>
<openerp>
    <data>
        <record model="ir.ui.view" id="wiz_registration_to_another_event_form">
            <field name="name">wiz.registration.to.another.event.form</field>
            <field name="model">wiz.registration.to.another.event</field>
            <field name="arch" type="xml">
                <form string="Change event to registration" version="7.0">
                    <group>
                        <separator string="New event for the registrations" colspan="4" />
                        <field name="new_event_id" nolabel="1" colspan="4"
                               domain="[('state','not in',('cancel','done'))]" />
                    </group>
                    <footer>
                        <button name="button_change_registration_event" type="object"
                            string="Change registration to selected new event" class="oe_highlight"/>
                        or
                        <button string="Cancel" class="oe_link" special="cancel"/>
                    </footer>
                </form>
            </field>
        </record>
        <act_window name="Change registration to another event"
                    res_model="wiz.registration.to.another.event"
                    view_mode="form"
                    view_type="form"
                    target="new"
                    id="action_change_registration_new_event"
                    key2="client_action_multi"/>
    </data>
</openerp>

<?xml version="1.0" encoding="UTF-8"?>
<openerp>
    <data>
        <record model="ir.ui.view" id="wiz_registration_to_another_event_form">
            <field name="name">wiz.registration.to.another.event.form</field>
            <field name="model">wiz.registration.to.another.event</field>
            <field name="arch" type="xml">
                <form string="Change event to registration" version="7.0">
                    <group>
                        <separator string="New event for the registrations" colspan="4" />
                        <field name="new_event_id" nolabel="1" colspan="4"
                               domain="[('state','not in',('cancel','done'))]" />
                    </group>
                    <footer>
                        <button name="button_change_registration_event" type="object"
                            string="Change registration to selected new event" class="oe_highlight"/>
                        or
                        <button string="Cancel" class="oe_link" special="cancel"/>
                    </footer>
                </form>
            </field>
        </record>
        <act_window name="Change registration to another event"
                    res_model="wiz.registration.to.another.event"
                    src_model="event.registration"
                    view_mode="form"
                    view_type="form"
                    target="new"
                    id="action_change_registration_new_event"
                    key2="client_action_multi"/>
    </data>
</openerp>

Put src_model in call to wizard "registration to another event".
[FIX] event_track_assistant: Put src_model in call to wizard "registration to another event".
