While it don't look like you will get the same answer twice here either for the most part I will add this. This is a G23 mag with the + feature on it. I successfully fired two shots out of the pistol. The one in the barrel and the next round that was in the mag. The rest I dumped out into my hand. This was a mag I never had problems with and never had problems with again when I removed the + feature.
What I think was happening is this...Under recoil of the gun the insert got caught in the floor plate. The spring didn't have enough upward pressure to correct the problem causing this "mess". Think of it like this... People replace springs all the time because they get weak. You have already weakened that spring by lengthening the area it is supposed to operate in.
For example take a spring that is made to maintain upward pressure in a area say for example 6 inches long. Take the same spring and put it in a area 7 inches long and it will not have the tension it is supposed to have and is now weak. Here is a pic showing what happened to mine.
You are looking down inside the mag the follower is on the bottom of the mag. The spring is still in it. It didn't have the umph to correct itself. I would recommend in addition to G22 springs also look at the +10% springs made by wolf. Here is a link to them. I use them to make sure something like that pic never happens to me in a time that would be real bad.
http://www.gunsprings.com/index.cfm?page=items&cID=1&mID=5#148