I had a couple of instances, including a checkout in a 172 when it popped when we were rolling for takeoff. I was a rated PIC receiving dual at the time, and I'm certain that I ran the check-list. Even today I suspect a prank by the CFI, although he acted innocent. I elected to abort the take-off.
Another time, I think I plain old was negligent or otherwise screwed up running the pre-taxi check-list. It was when I visited our friend Jay at Port Arransas.
In Carlson, I had a door pop open by itself. Again, I knew it was a matter of when, because of the latch design that used friction. So one day I started slipping to land and the door flew up and slammed the wing. What's amazing though, there was no damage at all. I thought the door handle would go through the wing fabric for sure, but nope. The door had just enough bend to prevent it. After landing, I modified the latch to lock the door mechanically, rather than with friction.