Right let me update you all...
I have 2 keys for my Renault Clio 2002, and I had one, I gave the other to my parents so they could move it about if they ever needed to.
Now I love the car BUT I had frequent problems with starting just as everybody described, it turns over but wont start. I resolved this by waiting a while (I took the key out and walked around) and trying again; when it would sometimes start.
I also noticed that for weeks at a time it would run fine, then suddenly - problems! Then they would be gone.
I came to this forum and found this thread and switched to my parents key. I'd told them about the problem before and they had said they'd never seen the problem...but they had been using the other key...
Well long and short of it is that I cleaned my key (thoroughly...with powertools etc - whatever I could
) and since my last post have had no issues AT ALL. Nada. Niet.
So try that first. Try cleaning both keys, try each key, and try spraying a LITTLE WD40 into your key barrel...if there's no contact there seems to be no start
It's funny too, because the previous owner (who didnt mention this problem at sale...) got about £500 worth of parts replaced to fix the problem, based purely on advice given by a garage. The problem continued, so he lost even more by selling the car, yet when I got it, the key he used was a little dull.
I hope this helps someone, and thanks to the first poster because it sure helped me!