Well, I bit the bulllet and got the latest CVS. After changing the CubeTest to use jsr231, all seems well.
I would recommend though that you guys update your downloadable build a little more often, and maybe update the demos so that they can use different renderers "out of the box". It would lower the initial frustration somewhat. It was easy for me because I'm on Mac OS X and CVS is "built in", but Windows people might not be happy with the trouble they have to go to just to get a working build. Also, it might help if there was a more prominent link on the xith3d.org page to the CVS - on initial glance, it looks like the release is all that is there.