I replaced mine with Autozone parts last time I did my brakes. Just this past weekend I found one sticking out towards the rotor. When I pulled them out and tried to reseat them the little "nubs" that hold them in are too small to do any retaining.
I told a friend about it and he said he knows a guy that the same thing happened to just a couple weeks ago (on an F-150, same pin design.) He had just replaced his with Autozone parts, as well.
Interestingly enough, if you look for them on Autozone's website they are not even available. I wonder if they got in trouble over it.
I parked the Ranger and ordered a set of Motorcraft pins from RockAuto, which came in today. They look heavy-duty compared to the parts store crap. Wherever you end up getting new ones, compare them with your old ones. If they look thin and the nubs are tiny don't install them. You don't want to cheap out on your brakes.