Hi I am currently having the same problem on my 98 megane, the only way around it is a rip off from Renualt involving having the car towed to the dealer and having the key re-coded. I have been told there is a manual over ride you can keyin but Renualt will not give it to you, I went to the dealer with all my documents but to no avail. You have been warned!
Un happy Megane Owner, April 2005