Hi
same issue here, one key works, one doesn't - the batteries went in one, and wary of the potential problems i replaced them with identical ones the same day - but it doesn't work, and yes, it's £150 plus VAT for "reprogramming" and i don't expect Renault mind the cash to effectively replace a battery.
I did manage to unlock it with a PDA, having "copied" the code using a tv remote control application, but it's not prctical - i'd love to have a plan C to start the darn thing while i wait a few paydays to give Renault their lb of flesh.
the saint, March 2006