Slim: ya siad - 'my own observation is that the action actually was working so fast it didn t grab the emty case'. Gotta bust your chops a bit here, but all in fun - you must have Superman's eyesight to have observed the slide working that fast.........
When your slide moves forward to chamber a cartridge the extractor should slide over the cartridge rim so that upon firing the slide retracts and the extractor pulls the spent case from the chamber and the slide returns to battery chambering another round. The extractor should have pulled each spent case from the chamber. Possibly some lubricant fouled the chamber and possibly when you cleaned the action you also cleaned the chamber allowing for positive functioning.
Something else too - these little pistols don't have large or heavy slides with lots of mass to help with chambering and extraction, and I would expect that just a little dirt could seriously impact the functioning of the pistol. Here's an example: my little Beretta 21A is the energizer bunny when it comes to plinking; it will go mag after mag after mag, until you fire off a couple of dirty rounds and then you can both see and feel it slowing down - a quick cleaning with a dry chamber brush and it is back to normal. So I would expect your pistol needs to be kept clean, or at least the chamber kept clean in order for it to run right.
Here's a test - when you clean the gun, remove the barrel - after cleaning the chamber and bore, insert a fresh cartridge and with the chamber facing up, or facing the ceiling, see how difficult it is to get the round out of the chamber just by flipping the chamber up - round should slide/pop right out - if not, the chamber is tight and it should be kept really clean - always swab the chamber dry. Also, since this is a pocket pistol it will pick up a lot of crap and lint from your pocket and that will jam the action.
I had to take one of my 1911s in for repair and the gunsmith gave it a good cleaning in the process, but complained about all the lint buildup in the gun and didn't see how the thing could run like that. I told him it runs just fine just like that but he didn't believe me. Now this is my main carry piece, so 6 mo later I felt it had sufficient lint buildup again, brought it to his shop/range, let him look at it to see that it looked as bad as when he had previously cleaned it and then proceeded to put 100 round downrange without a hic-cough.
My little Beretta 21A would not have been able to run like that as it needs to be kept much cleaner and lint free, and the slide does not have sufficient mass to function properly the piece properly when it's dirty. I suspect it may be the same with your Kel-Tec and that you may have to keep it clean. HTH. Mikey.