I am noticing this with G 2.1 Tomcat. May be applicable to G 2.1 Jetty distribution too.
I have created a second server instance with name i1 by copying the var directory to <g_home>/i1. While tomcat is logging to <g_home>/i1/var/catalina/logs, Web Access Log Viewer for this instance is still displaying log entries from the base server (i.e. from <g_home>/var/catalina/logs)!!