open your [magento]\app\etc\modules\Mycompany_Modulename.xml
<?xml version="1.0"?>
<config>
<modules>
<Mycompany_Modulename>
<active>true</active>
<codePool>local</codePool>
<depends>
<Othercompany_Modulename/>
</depends>
</Mycompany_Modulename>
</modules>
</config>
above code force Othercompany_Modulename
to load first.
hope this help you