I'm having a similar problem with my car... mk2 ph2 clio also.
When I first got the car the button or auto locking didnt work...about 3 weeks ago it started working of it's own accord. And now what'll happen is I'll get in the car, all fine, reach 4mph and it'll lock, then after a couple of minutes it'll start randomly unlocking and relocking itself. This started a few days ago.Then today I'd been shopping, came back to the car and unlocked it with the button on the key, before i'd taken a step closer it'd relocked itself, so I unlocked it again and put things in the boot, as soon as the boot closed(as soon as it made contact) it locked itself again. So I had to unlock it again! Then all the way home it was locking and relocking itself at random intervals. And after I'd parked at home and was getting things out the boot, it locked before the boot was shut. So I shut the boot, unlocked and relocked it. When I came back out a few hours later with my boyfriend to have a look at it, it'd unlocked itself.
My boyfriend and I took the automatic locking button off, and out of the dash but the problem still continued when we went for a little test drive. So we know its not the button. After refitting the button we tried to hold the button down til the dash beeped to turn it off but after about a minute it'd beep again and reactivate itself and the problem continued. We checked the appropriate fuses, took them out and put them back in but it still did not solve the problem.
Any other ideas!?