The original magazines had no stagger slot. They did not perform and we replaced with mags incorporating a 1" rim stagger slot. These worked fine. In about '06 Walther revised these mags by shortening the stagger slot in an attempt to correct something else. It neither corrected the issue and ruined the function of the magazine. Shortly thereafter the B series of magazines were released. I was sent a half dozen prototypes to test. I could not find anything wrong with their performance. In a 100% pistol, when I installed the short slot mags I had stovepipes, jams and live rounds jumping out of the pistol while the 2nd round was chambered. Don't ask me how. I don't know.
If you have either the original or the short slot mags Walther will replace them if you are having issues. The key is issues, if you are having problems with the mags tell them. Otherwise magazines need to be disassembled and cleaned just like any other part of the pistol. They are as important to the proper function of a semi auto firearm as any other part. M1911