log4j:ERROR any idea ?

[pincopallo_it]

log4j:ERROR Could not instantiate class
[org.apache.log4j.ConsoleAppender].
java.lang.ClassNotFoundException: org.apache.log4j.ConsoleAppender
at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:299)
at java.lang.ClassLoader.loadClass(ClassLoader.java:255)
at
java.lang.ClassLoader.loadClassInternal(ClassLoader.java:315)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:120)
at
org.apache.log4j.helpers.OptionConverter.instantiateByClassName(Optio

it seems it does not real the log4j.properties as cant find the classes
but IT IS in the classpath !!!!

any idea ?
Thanks
Gianni