When you seat a magazine, fully loaded or not, can you pull it out without activating the magazine release. If so, you have issues with either the mags or the catch location being out of spec i.e. something is not fully engaging. If its difficult or impossible to remove the mag without activating the catch, then it could be an issue of the jarring of recoil activating the catch. When compared to the XD and 1911 my MP9 has a very light button. It may be something as simple as bending the steel wire acting as the catch spring to increase the force required to activate the catch. Not sure if doing so will negate your warranty though.