make sure the path to the custom folder is correct Bud, and you are looking at the single custom load/save menu at left of screen, not the normal load menu.

The advantage of backing up groups of folders of related files in Song Manager and then making a big card from a successively merged backup of these groups is that when you decide you don't like the order of folders on the big card, or want to create some empty folders on it, you can rearrange the order of the groups of folders more easily just by rearranging the merge order. See Walt's post below, it only takes a few seconds to merge up some big cards with Song Manager, and you maintain all your long file renaming etc.