Caption2 (the one that is lighter in weight) is styled to be normal, where the first one is bold.
Regarding the ken burns effect on the slideshow, it still works fine for me but I am guessing it might get that hang up for you due to something that relates to your environment (browser and version, host server, even the computer(s) you use). As mentioned, the ken burns effect is a very resource intensive effect that needs a lot of processing power. Many sliders include that effect…. does the hang up happen for you when you view the demo site for this theme? http://demo.styledthemes.com/circumference/