[FIX]:

add sample email address to demo user and admin user, like:
demo@example.com
admin@example.com

bzr revid: apa@tinyerp.com-20121029101957-2n568lfdmaorxyba

openerp/addons/base/base_data.xml

@@ -69,6 +69,7 @@
             <field name="name">Administrator</field>
             <field name="company_id" ref="main_company"/>
             <field name="customer" eval="False"/>
+            <field name="email">admin@example.com</field>
         </record>
 
         <record model="res.users" id="base.user_root">
@@ -77,6 +78,7 @@
             <field name="company_ids" eval="[(4, ref('main_company'))]"/>
             <field name="menu_id" ref="action_menu_admin"/>
             <field name="signature">Administrator</field>
+            <field name="email">admin@example.com</field>
         </record>
 
         <record id="main_partner" model="res.partner">

openerp/addons/base/base_demo.xml

@@ -5,6 +5,7 @@
             <field name="name">Demo User</field>
             <field name="company_id" ref="main_company"/>
             <field name="customer" eval="False"/>
+            <field name="email">demo@example.com</field>
         </record>
         <record id="user_demo" model="res.users">
             <field name="partner_id" ref="base.partner_demo"/>
@@ -13,6 +14,7 @@
             <field name="signature">Mr Demo</field>
             <field name="company_id" ref="main_company"/>
             <field name="groups_id" eval="[(6,0,[ref('base.group_user')])]"/>
+            <field name="email">demo@example.com</field>
         </record>
 
         <!-- new rate for demo transactions in multi currency -->