"Either way it should Just Work."
Yeah, that is what I thought also. (I verified all your other suggestions, everything is correct).
What is really weird, is that if I remove the filter from the web.xml there are no issues using any of the other classes in the common jar file.
My wild guess is that the app server is trying to load the Filter as defined in the web.xml before it is aware of the WEB-INF/lib directory?
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