I agree with Dave Bell the idle problem is caused by a slight timing issue in the engine management software.If you go to renault for them to retune your Engine management it will cost you around £40.
There has been a known fault with most renault clios doing this and it is i beleive something they do check when having your service with them. Another known problem with Clios is the throttle body packing in and only allowing your clio to do about 30mph. Luckily mine went when it was still under warranty otherwise would have cost in excess of £400. If you ever need your throttle body replaced then make sure they also check the wiring loom connected to it as once i had mine done the same warning light came on and after renault investigating it found it to be the connecting block from the loom to the throttle body. Thankfully again this was also done under the warranty. 2days before the warranty expired in actual fact.
Hope some of this info has helped.
Jon
Jon Williams
July 2007