Renault Megane boot lock unlocks itself and opens 06?

My Renault Megane boot seems to unlatch itself when statonary or about to pull away it is an intermmittent fault but is getting worse.

We shut the boot then here the latch open as if we've pressed to boot latch to open it ourselves. It also does it when you use the central locking button. Once slammed shut it works again. Sometimes it wont open at all... please dont tell me to take it to a garage or dealer, if I was going to do that I wouldnt be asking this question here ;-)