XANTIA TD ESTATE ALARM

[Doc]

A friends P reg Xantia Estate TD started to suffer central locking problems. Firstly the car decided to lock her in and the only way to get out was for someone to open the drivers door from the outside and secondly, when using the keyfob to lock the car, the central locking cycled open and shut very fast and then remained in an unlocked state.
The keyfob has had a new battery by the way.
The car also has a keypad start which I've heard can cause problems.
Any advice greatfully received as she doesn't want to be locked in
Doc

[modi]

I had similar issue with mine, I used wd40 on the doors -where the lockers are- which was realy helpful, it does it couple of times per month now but I found out that waiting for 10 to 20 sec after I close the doors then using my keyfob to lock it is good as if it needs to settle..