At a specific project in the US, colleagues of mine faced the "RMIConnection Disconnected" issue. Unfortunately, this wasn't a problem that could be easily solved like in my earlier post on that one.
This one is different as it involves two different OC4J/AS versions (10.1.2 and 10.1.3). It is really a bug and fixed in patch 6114217 for OC4J/AS 10.1.3.[012] and also made it into the 10.1.3.3 one-off patch 6148874.