Ok, there seems to be an issue with Safari where the slider just stops after awhile. It doesn't stop in FF. Since I previously used a jQuery slider similar to this one (which did stop when the mouse was over the image), I assumed that is what was happening here.
BUT I am having a difficult time reordering the images for the slider. The modal popup which is described in your Theme Documentation doesn't show for me (maybe WP 3.3.2 changed something).
When I upload an image via the media uploader, or the new media uploader and click "Save all changes", it take me directly to the full-screen Media Library. In this whole process, there is no "Gallery" option to click which is supposed to take me to the functionality whereby I can set the ordering of the slide images.
Media > Media Library > Add new (link) > Upload New Media (page) > Choose File (or) Switch to new file uploader (links - both takes me directly to choosing a file from my computer. No other options). > (file uploads) Save all changes (button) > (takes me back to) Media Library. (No "Gallery" option).
I believe I was in error. I was previewing in Safari, left the computer for a few minutes, when I came back the slider was stalled, the mouse happened to be over the slider. I've used a few different jQuery sliders and all or most paused when the mouse was over the slider, so I assumed that is what was happening. This is not happening in FireFox.
It seems to be some issue with Safari where the slider stops after a certain amount of time, i.e. not related to the performance of the slider.