Are they all happening in the morning? maybe when the user is first using the Baan GUI? I ask because we just had a user complain about the same kind of problem, however it turns out that she is trying to use the GUI that she has left it running overnight. This means after the overnight back-up when Oracle is shutdown/restarted.
Not sure it is the same, but thought I would mention it.
Best of luck
Stephen J. Sellens