I don’t think this is a theme issue, the plugin has its own files that it relies on to display and function properly….so if it’s not showing up, it could possibly be the plugin itself causing the issue (it could also be a Windows 8 bug as well).
There is one place in the theme’s style.css file that deals with the arrows, but the only thing it does is slightly move it over a little bit, I doubt that is the reason it won’t show…..but just in case, take a look in your css file around line 2272 for the following code –
.flex-direction-nav li .prev {
left: 0 !important;
}
.flex-direction-nav li .next {
right: 0 !important;
}
…try removing that code….hit reload (clear your browser cache) and see if that makes a difference. If it doesn’t, then there is definitely something else preventing them from showing up.
That’s about as much as I can offer since I didn’t create the plugin myself and I don’t have access to Windows 8 just yet (Mac user). If the above suggestion doesn’t work then I’d recommend heading over to the StudioPress Community forums where one of the actual developers of this plugin can offer some assistance since they would know better than I would.