Here is the answer I found. I think it stinks.
"You can sort in any single level view. So any folder without subfolders, any collection without subcollections, any keyword without subkeywords. Get the idea? If you do need to do a custom sort in a folder with subfolders, turn off 'include photos from subfolders' under the Library menu.
The other thing that always trips people up is HOW to grab the files. You need to pick them up by the centre of the thumbnail itself. I'm sure you probably know that, but it's worth mentioning for those who don't."