eiru_account_interest/views/data_decimal_precision_interest.xml

<?xml version="1.0" encoding="utf-8"?>
<openerp>
    <data noupdate="1">
        <record forcecreate="True" id="decimal_payment" model="decimal.precision">
            <field name="name">Interest</field>
            <field name="digits">6</field>
        </record>
    </data>
</openerp>