Here's what was wrong. The reason the wedges were falling out was partially because the treads and risers were not correctly sized for where they were being installed. The pic sucks. The others disappeared sorry. I'm in the habit of routing my stringers, setting them without nailing them, installing bottom tread and riser, then pushing the top up, installing the nosing at the top then lowering it to where its' going to be. From there, I secure the stringers, then cut every one of the treads and risers to fit. Glue wedge ect. So, either one of two things happened here. Either the guy put the whole thing together at once then busted his ass stuffing it in the well and spread it when he secured it, or they cut a pile of treads the same length and, expected there would be no variation in the distance between the walls as he went along, found out different, and installed them anyway with a minimumum amount of the tread in the stringers and stuck them in anyway. People used them, and the wedges loosened up. If they did them individually in the first place, there wouldn't be anyway or any where they could have moved. I had the method I use, beat into my head by a mean old schooler back in my early twentys. I never had a problem, they have always gone in fast, And I never went back to fix a set. I make my own jigs out of half inch plywood, and have never owned any stinking Stanley jig. Now that I'm old and have had to rip other's garbage out and replace it more than a few times, I Ain't changing they way I do it.