I am using alfresco 4.0. I have added a logger to "Review and Approve" workflow . but i am not able to see the logger statement in alfrescotomcat-stdout.log file.
You should modify file "log4j.properties" from folder $TOMCAT_HOME/webapps/alfresco/WEB-INF/classes/log4j.properties. After that, you will see log entries in "stdout_<TIMESTAMP>.log"