Soaking beans before cooking is a widespread practice. Another widespread practice is, before cooking rice, to spread it on a flat surface and remove stones or rotting grains.
After soaking beans, some separated skins float. Even some beans float. Should those be discarded? Are the floating beans infiltrated by some insects?
EDIT: So the last comment and the only answer contradict each other. Which one is it?
In other news, the beans in question were dirt cheap and turned out completely tasteless. However, when I've soaked beans in the past I've always gotten some separated skins (but no floating beans) - just not so many. So I don't know if these were tasteless because of being old or some other reason.