Stozza,
I have just had exactly the same problem with my Clio 1.2 16V. The problem you describe is what I've experienced down to the letter. How much did this cost you to repair minus the days labour to find the initial fault? I am currently debating whether to keep my Clio as I haven't stopped opening my wallet since getting it only 6 months ago. Since getting the car I have replaced ECU, 1 drive shaft, cam belt, water pump, CV joint, exhaust mounting and a few other minor things.
Thanks in advance.