When is a locked door not a locked door?

We have slowly come to the conclusion, though my roommate more quick on the uptake than I, that people have been repeatedly trying to rob us at our house. We think that they've come in and taken stuff of his. The odd thing is it's small stuff, like a calculator of mine, but the computers are left behind. And there is no trace of entry. Except for scratches around the lock, the lock not working right, the appearance of someone trying to jimmy the lock. The other day someone went on to the roof to steal my roommate's $200 wetsuit and all the neighbor's clothes- there are three Americans in this building in the middle of the ghetto, and someone has gotten the idea that this is the place to find expensive things (comparatively speaking). The sad thing was that in the last case, it was the poor neighbors who got most robbed.

We've had to change the lock now 3 times- including today. Collin came home and the maid told him the lock had been pushed in when she tried to open it, 'cause someone had been playing with it. So they changed the lock, and Collin slipped a new key into the mailbox for me.

It kind of looked like the old key. Now, I know I might be a bit extreme here, but I'm thinking, when a locksmith changes the lock, they should actually put on a new lock, n'cest pas? Not here, evidently. Old key worked just fine. Same lock. Got a new lock installed, but not really. Be great for anyone who has been slowly working on our old lock in the past- they don't have to learn anything new!