[rules-dev] log4j.xml

I find that one of my applications (a webapp running on jboss-4.2.1ga ) stops logging when I added drools. Actually it does not entirely stop logging, but it just becomes very very quiet (ERROR only). After some digging I discovered that drools-repository.jar contains log4j.xml and when I deleted that file from the jar, my webapp logging returned to normal levels. Is this expected behavior?