So if this file does exist and you have
needed permissions to access and edit it, than doesn't the application shows some log4j warnings?
Usually in such cases (no warning message, no logs) I had some problems with multiple log4j JARs in the classpath. Maybe your
tomcat server is configured different on your Windows box and Unix? Check the server-level libs for differences.
You can also check the extensions directory (i.e. /usr/lib/jvm/java-6-sun/jre/lib/ext) for possibly conflicting JARs.
Also - no errors in standard output - catalina.out file?
Cheers!