I have a possible bug in JBoss Cache, but I'm not sure...

I'm using Objects (not Strings) as Fqn's, in a PojoCache, and later, calling the PojoCache.findObjects() method, I obtain a ClassCastException. Diving into code, I watch this (in TreeCacheAopDelegate.java):

protected void findChildObjects(Fqn fqn, Map map) throws CacheException
 {
 // We need to traverse then
 Set set = cache_.getChildrenNames(fqn);
 if(set == null) return; // We stop here.
 Iterator it = set.iterator();
 while(it.hasNext())
 {
 String obj = (String)it.next();
 Fqn newFqn = new Fqn(fqn, obj);

 Object pojo = _getObject(newFqn);
 if(pojo != null)
 {
 map.put(newFqn, pojo);
 } else
 {
 findChildObjects(newFqn, map);
 }
 }
 }

The objects contained in the set (which is the result of getChildrenNames() function) aren't Strings, so the cast to String fails.