Every time you hear of an application that only works on a specific release of the JRE you can know for sure it's because they use undocumented internal API's — keep in mind this not only impacts compatibility with other releases of OpenJDK/Oracle JDK, but the sun.* API's are not typically part of third-party JVM's like JRockit or the IBM JVM.
Stop using internal API's and then bitching when Oracle makes changes to them, you only have yourself to blame.