Hello. I have a TiVo HD-Almost 5 years old now and I have an external HD hooked up to it. In the past week I have noticed the following behavior. In 3 separate programs I recorded-at a certain spot in the episode, the TiVo will freeze and the remote will become unresponsive. After about 20 seconds it will resume. Any attempt to return to that point in time will yield the same behavior. And other than this, the TiVo is behaving just fine. Should I be concerned?