Well, I fiddled with the spring last night and ensured that it was slipping into the groove on the slide stop. I fired 76 rounds through it this morning and had no malfunctions. I do have the impression that if you use the slide stop to drop the slide on a fresh magazine (instead of pulling the slide back and releasing it), the slide stop is more likely to back out.
The gun is shooting well and I really prefer it to my Glock 30SF. I think I will sell my Glock and promote the Kahr to my main carry gun (along with my J frame Smith).