Just to update i've noticed that this is the same for the inside handle as well.
If the doors are locked, then unlocked I have to pull the handle twice before the door opens.
If the doors are not locked in between the handle only needs to be pulled once.
This is the same getting in or out of the car. - Weird!!
Does this sound like an anti-hijack thing or is there a problem with the lock?
Thanks
Martin