In a Clustered JIRA ProjectImportResultsImpl is not serializable and causes NotSerializableExceptions when the task cache is replicated.

2014-08-01 07:15:53,459 main WARN [net.sf.ehcache.CacheManager] Cache com.atlassian.jira.task.TaskManagerImpl.taskMaprequested bootstrap but a CacheException occured. Error bootstrapping from remote peer. Message was: error unmarshalling return; nested exception is:
java.io.WriteAbortedException: writing aborted; java.io.NotSerializableException: com.atlassian.jira.i18n.BackingI18n
net.sf.ehcache.distribution.RemoteCacheException: Error bootstrapping from remote peer. Message was: error unmarshalling return; nested exception is:
java.io.WriteAbortedException: writing aborted; java.io.NotSerializableException: com.atlassian.jira.i18n.BackingI18n
at net.sf.ehcache.distribution.RMIBootstrapCacheLoader.doLoad(RMIBootstrapCacheLoader.java:176)
at net.sf.ehcache.distribution.RMIBootstrapCacheLoader.load(RMIBootstrapCacheLoader.java:77)
at net.sf.ehcache.Cache.bootstrap(Cache.java:1364)
at net.sf.ehcache.CacheManager.initializeEhcache(CacheManager.java:1388)
at net.sf.ehcache.CacheManager.addCacheNoCheck(CacheManager.java:1437)
at net.sf.ehcache.CacheManager.addConfiguredCaches(CacheManager.java:839)
at net.sf.ehcache.CacheManager.doInit(CacheManager.java:498)
at net.sf.ehcache.CacheManager.init(CacheManager.java:392)
at net.sf.ehcache.CacheManager.<init>(CacheManager.java:265)
at net.sf.ehcache.CacheManager.newInstance(CacheManager.java:1123)
at net.sf.ehcache.CacheManager.newInstance(CacheManager.java:1099)
at com.atlassian.jira.CacheManagerRegistrar.getCacheManagerDelegate(CacheManagerRegistrar.java:130)