Rear door locking

Hi all,

I've recently had the rear door apart to do the leaking door fix.

I've not noticed it before as it's my wifes car and not mine, but ever since, the rear door doesn't always open. I does appear to actually unlock as I can hear and feel the 'clunk' when the lock opens, as with every other door. Sometimes the handle needs a good yank. Any ideas lads? Cheers.