[Plugin: NextGEN Gallery] Custom Sorting

So, I’ve just downloaded the most recent version of NextGen Gallery and uploaded some 30 pictures. The ID order they were put in is wrong, however, and I can’t find the sort button. Some of the older posts here have mentioned that “Custom Sorting” needs to be turned on through the Options menu, but I’ve looked through all seven of the Options Submenus and don’t see anything like that. What’s wrong?

And is there a FAQ explaining how to take advantage of this plugins obviously copious features rather than just listing off what they are?