I actually didn't code it for 1.3, it was just what I was using. Something in Xerces/xalan xml jars causes the app to run out of memory with 1.4. If anyone knows why this is, I'd love to take advantage of some of the 1.4 features.
FYI, 1.4 has a terrible history of not being compatible with 1.3 apps. It's very unfortunate.