>Have you changed something on the view of Shop from Admin menu?
Definetely not. In my opinion the field was somehow cleared by xml demo-data of some unready addon, but i couldnt find the one.


[openerp@fedora openerp]$ for i in $(find -name *.xml); do grep -Hn warehouse_id                                                                               $i ; done
./addons/purchase/test/purchase_test.xml:12:            'warehouse_id': fields.m                                                                              any2one('stock.warehouse', 'Warehouse', states={'posted':[('readonly',True)]}),
./addons/purchase/purchase_data.xml:41:            eval="('default',False,'wareh                                                                              ouse_id', [('purchase.order', False)], ref('stock.warehouse0'), True, False, Fal                                                                              se, False, True)"
./addons/purchase/purchase_unit_test.xml:12:            'warehouse_id': fields.m                                                                              any2one('stock.warehouse', 'Warehouse', states={'posted':[('readonly',True)]}),
./addons/purchase/purchase_view.xml:43:                        <field name="ware                                                                              house_id" on_change="onchange_warehouse_id(warehouse_id)"/>
./addons/purchase/purchase_view.xml:186:                            <field colsp                                                                              an="4" context="partner_id=parent.partner_id,quantity=product_qty,pricelist=pare                                                                              nt.pricelist_id,uom=product_uom,warehouse=parent.warehouse_id" name="product_id"                                                                               on_change="product_id_change(parent.pricelist_id,product_id,product_qty,product                                                                              _uom,parent.partner_id, parent.date_order, parent.fiscal_position)"/>
./addons/purchase/purchase_view.xml:187:                            <field conte                                                                              xt="partner_id=parent.partner_id,quantity=product_qty,pricelist=parent.pricelist                                                                              _id,uom=product_uom,warehouse=parent.warehouse_id" name="product_qty" on_change=                                                                              "product_id_change(parent.pricelist_id,product_id,product_qty,product_uom,parent                                                                              .partner_id, parent.date_order, parent.fiscal_position)"/>
./addons/sale/sale_view.xml:14:                    <field name="warehouse_id" re                                                                              quired="1" select="1"/>
./addons/sale/sale_view.xml:33:                    <field name="warehouse_id"/>
./addons/sale/sale_data.xml:27:            <field model="stock.warehouse" name="                                                                              warehouse_id" search="[]"/>
./addons/mrp/mrp_order_point.xml:11:            <field model="stock.warehouse" n                                                                              ame="warehouse_id" search="[]"/>
./addons/mrp/mrp_order_point.xml:19:            <field model="stock.warehouse" n                                                                              ame="warehouse_id" search="[]"/>
./addons/mrp/mrp_order_point.xml:27:            <field model="stock.warehouse" n                                                                              ame="warehouse_id" search="[]"/>
./addons/mrp/mrp_order_point.xml:35:            <field model="stock.warehouse" n                                                                              ame="warehouse_id" search="[]"/>
./addons/mrp/mrp_order_point.xml:43:            <field model="stock.warehouse" n                                                                              ame="warehouse_id" search="[]"/>
./addons/mrp/mrp_order_point.xml:51:            <field model="stock.warehouse" n                                                                              ame="warehouse_id" search="[]"/>
./addons/mrp/mrp_view.xml:789:                    <field name="warehouse_id"/>
./addons/mrp/mrp_view.xml:805:                    <field name="warehouse_id" on_                                                                              change="onchange_warehouse_id(warehouse_id)" select="1"/>
./addons/mrp/mrp_view.xml:825:        <act_window domain="[('warehouse_id', '=',                                                                               active_id)]" id="act_stock_warehouse_2_stock_warehouse_orderpoint" name="Minimu                                                                              m Stock Rules" res_model="stock.warehouse.orderpoint" src_model="stock.warehouse                                                                              "/>