Tomcat 4 monitoring - problems with valve loading

Hi,

I've installed the tomcat4agent as asked in the tomcat directory on a linux server.
When i launch tomcat, here is the log i got in the catalina.out :

ServerLifecycleListener: Creating MBean for Valve com.adventnet.appmanager.tomcatagent.ver4.valve.AdventNetHostValve@8ee016
ServerLifecycleListener: createMBeans: MBeanException
java.lang.Exception: ManagedBean is not found with AdventNetHostValve
at org.apache.catalina.mbeans.MBeanUtils.createMBean(MBeanUtils.java:763)
at org.apache.catalina.mbeans.ServerLifecycleListener.createMBeans(ServerLifecycleListener.java:436)
at org.apache.catalina.mbeans.ServerLifecycleListener.createMBeans(ServerLifecycleListener.java:681)
at org.apache.catalina.mbeans.ServerLifecycleListener.createMBeans(ServerLifecycleListener.java:620)
at org.apache.catalina.mbeans.ServerLifecycleListener.createMBeans(ServerLifecycleListener.java:813)
at org.apache.catalina.mbeans.ServerLifecycleListener.createMBeans(ServerLifecycleListener.java:781)
at org.apache.catalina.mbeans.ServerLifecycleListener.createMBeans(ServerLifecycleListener.java:325)
at org.apache.catalina.mbeans.ServerLifecycleListener.lifecycleEvent(ServerLifecycleListener.java:179)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119)
at org.apache.catalina.core.StandardServer.start(StandardServer.java:2136)
at org.apache.catalina.startup.Catalina.start(Catalina.java:463)
at org.apache.catalina.startup.Catalina.execute(Catalina.java:350)
at org.apache.catalina.startup.Catalina.process(Catalina.java:129)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:156)