Well, after testing the latest I just reproduced the UnsupportedOperationException issue you described in your last posting. Greenhouse is pushing the envelope with regard to Spring Framework 3.1 features, and as a result depends on the latest 3.1.0.BUILD-SNAPSHOT. Unfortunately, it seems like some of the recent enhancements to Spring MVC have broken the application. I've reported the issue to Rossen who is responsible for those changes and expect they'll be addressed soon. I would revert back to 3.1.0.M1 in the meantime, but Greenhouse now depends on some post M1 fixes as well so I'm kind of stuck until the next snapshot that fixes the MVC issues.
Core Spring Development Team