[banddr2]

The only thing I can think of right now, is remove the right grip and look at where the end of the trigger bar inserts into the cocking piece. Maybe there is a metal burr there, or something rough or dirty, maybe contact points did not get finished as they should of from the factory. I am pretty sure that's is where the trigger resest to SA mode. Could also be a broken trigger spring, but I think that would be unlikely.

 

[banddr2]

Thanks for the advice. Next question, what does the trigger spring look like, and how does it mate to the trigger bar. I don't think my PPK has one! Only by fussing with the trigger bar can I get the problem to repeat. It looks like the trigger bar is failing to move up into the cut-out on the slide from time to time.

I think there should be a spring under your trigger bar, look at the schematic on this site:

http://www.e-gunparts.com/productschem.asp?chrMasterModel=2100zPPK