Also had this problem with my 04 Scenic. Worrying, as without the boot closed, the car is not lockable being all electronic. I pushed the visible lever on the lock across with a screwdriver and sprayed with WD40 which seems to have fixed the problem . Now seems fine. Wish I'd tried using WD40 when the cam belt went at 40k miles. Might have saved me £1900 repair bill.
John B
May 2009