Hi, I realise that this thread ended a while back....I have just had the same problem. Today, sparks shot out of my straighteners from the area around the ceramic plates. Following this a flame ignited through the cord at the end nearest to the ceramic plates. After a couple of seconds, the flame died away. I have the straighteners since December 2003 but to be honest they have only been used on average twice a week, not "heavy" usage by any standard.
I emailed GHD today and after reading the information here, am eagerly anticipating their reply.....did anyone have any success?