Greg
Greg - I am sure this might feel like disapointment, however there are two main things to consider. First - screws do that all the time, especially when connecting two moving parts (dont thing about it as a spring axle) - this is absolutely normal thing, not uncommon, and much more expensive watches can have similar problem. However - the routine, and also good advice from many watchmakers is to either use a drop of glue, or even the nail varnish to the top end of the screw to ensure the screw on place. It is a practise known also in autosport, and many other things and products dealing with screws on vibrating, turning, moving or exposed places. Last thing - there is not proper and definitive technical solution to this, principally. You could put a nut on the second end of screw, via outside drilled link, to get thing done. Now consider the aesthetics of that. So as you can see, there is not much ground to play on. Also considering the price/ratio value, it would be pitty for yourself to loose trust for product/brand offering one really a lot, for peanuts - just for minor thing, which is quite normal and not a big deal. Enjoy the watch. They deserve it !