Grails log4j version clash with a third party java API

I have to use a third party Java API from Cisco which uses an older version of Log4J i.e. 1.1.3 When run standalone, obviously API works fine but when run from Grails (1.3.7), it crashes with some "Operation not found" exception during Log4j initialization. How can I resolve this clash? Here is the BuildConfig actual plugin that contains the cisco lib in the lib folder.