Never refer to the same JAR using Class-Path from two different modules. (It will get loaded twice and could cause strange problems.) If you think you need to, generally this just means you have not factored out your module dependencies thoroughly: split off a third module to hold the library.
Ninus Khamis, René Witte, and Juergen Rilling. 15th International Conference on Applications of Natural Language to Information Systems (NLDB 2010), 6177, page 68--79. Cardiff, UK, Springer, (June 2010)