Boy are you right! I tried my cheap new Promag for my Compact last night, and the same thing! After the first, they nosedive! I even tried the other two on the shelf, and the same thing. I do have one Promag that works, but from now on it's CZ mags. My boss did suggest a Wolf power spring for the Promag, but with the $9 the mag cost, I might as well get the good stuff.