Java Introspection

About two weeks ago at work we got into a classic "works fine in development / doesn't work in staging" situation. I finally tracked it down to the fact that development and staging are running slightly different versions of Java. This surfaces because one of the Struts forms doesn't follow the standard for indexed properties. Evidently, version A of Java 1.3 handles introspection differently than version B. After working this out, I was able to jam the JRE from WebSphere in staging into the appropriate place in WSAD and now development breaks just like staging. Apparently this isn't an uncommon issue in Java 1.3 land, but from newgroups it sounds like it generally surfaces with an InvalidArgumentException rather than silently failing.