<A target="_blank" href="http://www.bobzblog.com/tuxedoguy.nsf/dx/the-2-headed-beast-debugging-domino-java-agents-with-eclipse">Bob Balaban revisits the problem of debugging Java agents</A> since Domino Designer in Eclipse doesn't have a debugger that will work for this problem. He's provided a link to his solution from 2007 which includes a PDF and a JAR.