Thank you for all your advice and suggestions. Apologies for the delay, but I was trying to sort this out before I went on holiday. I tried just about everything that you all suggested after I returned from holiday, and then after Christmas we decided to return the 5000T to Curry's. Eventually it was replaced with a new one, and (for now) it works perfectly. After all this, it was obviously a faulty recorder. Time will tell if the replacement goes the same way.