505 broken door latch, won't lock! please help!

[jmlabez]

I have a weird problem with my driver's side door. I'll lock the door and shut, and as soon as the latch hits the frame, it pops into the open position. When I close the door, and lock it, it doesn't actually lock the door, because if you pull on the handle, it pops up and opens.

As far as I can tell, it the door latch doesn't click into the locked position. I can manually flip the latch into the locked position but it doesn't allow me to close the door. Reset that. Try to lock the door and shut it.. up goes the lock on the top of the door. I can click the lock from the inside but it still opens. Anyone have any idea how to fix this? I'm really new to Peugeots...