here's a thread from august....you remember, earlier in the year mid summer when it was well over 100 degrees in a lot of places in the u.s. 
Finally, my local dealer had one and I ploped the money down lickety split. First range day sucked, I was beside myself. Shot 100 rounds and had multiple FTE's and a few stovepipes. Not limpwristing. Went home, pondered the expert's advice ( from "walther Forum-PPS" thread), and decided to take the thing apart. I cleaned and lubed the mags, the gun, and noticed my trigger was sticky if I let it return slowly. I then removed the striker assembly and noticed there was a chunk of powder or plastic that was in the firing pin channel and I removed it. That fixed the trigger issue as it now was less gritty and returned more briskly. Back to the range, 150 flawless rounds-problem solved, happy camper. Accurate, with low recoil. AWESOME.
I absolutely love this thing. I have been wanting an ultrathin 9mm of quality european design/construction for a long time. You don't even notice this thing in your waistband. Kudos to Walther for having the insight. Now, I can't wait for the .40, although I think 9mm is optimum in these smaller weapons. Good shooting.