After what looks like all appropriate configurations are performs to use logback with Spring web application a "SEVERE: Error listenerStart" is shown by Tomcat on the application start. Any ideas? The details of environment and configuration are below.

Java 7
Tomcat 7
Spring 3.1.4
slf4j 1.7.5
logback-ext-spring 0.1.4

logback.xml:
<configuration debug="true">
    <appender name="appLogFile" class="ch.qos.logback.ext.spring.DelegatingLogbackAppender"/>    
    <root level="debug">
        <appender-ref ref="appLogFile" />
    </root>
</configuration>


web.xml:
....
    <listener>
        <listener-class>ch.qos.logback.ext.spring.web.LogbackConfigListener</listener-class>
    </listener>
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
....

spring-app-config.xml:
....
    <bean class="ch.qos.logback.ext.spring.ApplicationContextHolder"/>
    <bean id="appLogFile" class="ch.qos.logback.core.FileAppender" init-method="start" destroy-method="stop">
        <property name="context" value="#{ T(org.slf4j.LoggerFactory).getILoggerFactory() }"/>
        <property name="file" value="${catalina.home}/logs/${app.name}.log"/>
        <property name="encoder">
            <bean class="ch.qos.logback.classic.encoder.PatternLayoutEncoder" init-method="start" destroy-method="stop">
                <property name="context" value="#{ T(org.slf4j.LoggerFactory).getILoggerFactory() }"/>
                <property name="pattern" value="%d{HH:mm:ss.SSS} %-5level %logger{36} - %msg%n"/>
            </bean>
        </property>
    </bean>
....