Spring MVC not logging all exceptions

I have Spring MVC setup to log exceptions using commons logging, but find that some runtime exceptions aren't being logged.

Here's my bean configuration for the default exception resolver provided by spring:

<bean class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver">
    <property name="exceptionMappings">
        <props>
            <prop key="java.lang.Exception">error</prop>
        </props>
    </property>
</bean>