[logback-user] ch.qos.logback.access.tomcat.LogbackValve overrides final method start

Hello, I tried to configure logback for tomcat 7.0.29 according to the instructions in "HTTP-access logs with logback-access, Jetty and Tomcat". But now I get an exception when I want to start tomcat that states ch.qos.logback.access.tomcat.LogbackValve overrides final method start. Is logback not compatible with tomcat 7? Regards Bernd