Central locking TD5ES

I have noticed over the last few weeks that when you blip the key fob a 2nd time to unlock the other doors, the front passenger, rear o/s passenger and sometimes the tailgate seem not to open properly, the buttons on the doors seem very lazy and you have to blip them again to get them to open. Has anyone encountered this before and has anyone got any suggestions. I know its not life threatening but its not right and I dont want the c/l to pack up alltogether.
Thanks, Paul

Its a door latch fault, you can try wd40 to lube them up but that doesn't normally work. give it a go though but really you need new latches.

Mine does this as well but only in cold weather - it all works fine in spring/summer/autumn