I had the same thing happen, but with only 1 screw, so I just think that the thumb screws are not particularly vibration resistant and come loose in transport. Silverstone might wanna put some plastic tape over them or something. Until I started tilting my case and heard the screw rolling around...
Not sure of what temps you are after, but at least the French and Norwegian reviews include pretty useful temperature comparisons - you find a list of all the current reviews at Silverstone's site http://www.silverstonetek.com/products/p_review.php?pno=FT02&area=usa