<?xml version="1.0" encoding="UTF-8"?>
<layout>
    <magemonitoring_overview_index>
        <reference name="head">
            <action method="addCss"><name>monitoring/css/apc.css</name></action>
            <action method="addCss"><name>monitoring/css/monitoring.css</name></action>
        </reference>
    </magemonitoring_overview_index>
</layout>
<?xml version="1.0" encoding="UTF-8"?>
<layout>
    <adminhtml_monitoring_index>
        <reference name="head">
            <action method="addCss"><name>monitoring/css/apc.css</name></action>
            <action method="addCss"><name>monitoring/css/monitoring.css</name></action>
        </reference>
    </adminhtml_monitoring_index>
</layout>
Handle name fix in layout update xml
Handle name fix in layout update xml
