[appengine-java] Persist Hashmap and PersistenceManager question

I followed the following thread (http://groups.google.com/group/google- appengine-java/browse_thread/thread/fb12ab60c68bf664/400cf3c83be90ce9? lnk=gstq=persist+hashmap) to successfully persist my hashmap. I had a hard time to get it working because of the following issue: If I use the following

[appengine-java] potential bug: Caused by: java.lang.IllegalAccessException: Reflection is not allowed on private final boolean java.util.LinkedHashMap.accessOrder

My application is running flawlessly on hosted and web mode (GWT 1.7.1 - GXT 2.0.1 - GWT-SL1.0). Once deployed on GAE , I have the following exception: javax.servlet.ServletContext log: Exception while dispatching incoming RPC call java.lang.RuntimeException: