contract/analytic_hours_block/security/hours_block_security.xml

<?xml version="1.0" encoding="utf-8"?>
<openerp><data>

    <record id="hours_block_comp_rule" model="ir.rule">
        <field name="name">Hours Block multi company rule</field>
        <field model="ir.model" name="model_id" ref="model_account_hours_block"/>
        <field eval="True" name="global"/>
        <field name="domain_force">[]</field>
    </record>

</data></openerp>