I was shooting with a group, who all had Kimber Customs except for the instructor who had a glock. We had some problems with failures to eject and failures to load because of the combination of bitterly cold weather and the fact that we were shooting semi wad cutters. After admonishing us for not using Glocks, he unloaded his gun (someone else checked it) threw it in the dirt (and I mean chunked it) and then proceeded to fire a full magazine with something like five malfunctions.
In Glocks defense he was using and after market slide.
In all seriousness I agree that the magazines should bear further examination.