I've set up a tree view and a search view for a simple model:

<record id="public_holidays_list_view" model="ir.ui.view">
             <field name="name">holidays.holidays.tree.view</field>
             <field name="model">holidays.holidays</field>
             <field name="arch" type="xml">
                    <tree string="Public Holidays" editable="bottom">
                          <field name="name"/>
                          <field name="date"/>
                          <field name="percentage"/>
                          <field name="year" invisible="1"/>
                    </tree>
             </field>
     </record>

     <record id="public_holidays_search_view" model="ir.ui.view">
             <field name="name">holidays.holidays.search.view</field>
             <field name="model">holidays.holidays</field>
             <field name="arch" type="xml">
                    <search string="Public Holidays">
                            <group expand="0" string="Group By...">
                                   <filter name="group_by_year" string="Year" icon="terp-project" context="{'group_by':'year'}"/>
                            </group>
                    </search>
             </field>
     </record>

     <record id="open_view_public_holidays" model="ir.actions.act_window">
        <field name="name">Public Holidays</field>
        <field name="type">ir.actions.act_window</field>
        <field name="res_model">holidays.holidays</field>
        <field name="context">{'search_default_group_by_year': 1}</field>
        <field name="view_type">form</field>
        <field name="view_mode">tree</field>
        <field name="view_id" eval="public_holidays_list_view"/>
        <field name="search_view_id" ref="public_holidays_search_view"/>
    </record>

The records are grouped, but not displayed, even if I expand the groups.
What is happening?
Further: I'd like the standard create button to still work while in search view.

Please help.