I've just started running into this myself, and could only come up with the same solution - consolidate a bunch of those folders with only one or two items, and move the basically unused ones elsewhere (backup or what have you.) Looks like Poser works best with about 100 folders or directories ineach library area, though my Poses libary seems a bit more finicky. Weird, and yeah, they need to come up with a better libraries interface.