My ignorance for the day: just picked up a 64GB microSDXC card and the computer was registering the size at a few scant KBs, not GBs, when I put the card in a reader and attached the reader to the computer; I thought that the card was a fake, although picked up at a reputable store, until I continued to experiment and saw that the laptop's internal card reader was reading the card at the full size. Took a quick Wikipedia course on the SDXC standard and learned, an hour into this event (and including a few formats later, just in case it was a card issue), that newer readers are needed to read SDXC cards (although, fortunately, the Clips can do so--bravo, SanDisk!).
Hard to keep up with technology and what the manufacturers assume we know or don't care enough to inform us about . . . .