I've seen people posting online (even on this forum I think) about problems with FR-V central locking. But usually the symptom is that one door will not lock or unlock, rather than all doors unlocking and then immediately locking again.
The actuators are obviously one per door so usually only one door is affected at a time - although once one goes the others can start to go too, it's unlikely they would all start playing up on exactly the same day.
Good luck with it - hope you manage to sort it out.