The card you linked to is a 32GB Class 10 card. Many people have reported problems using Class 10 cards in mp3 players (particularly in this case the Sansa players), and phones. Class 10 cards are designed for use with cameras (still and video) where high-speed writing in needed. This post explains it more in detail. It’s basically a matter of using the wrong tool for the job at hand.
Whether the card is defective or you’re running into this compatibility issue, I don’t know but it sounds like a new card is in order. SanDisk should probably replace it under warranty, but if you get another Class 10 you may run into the same thing again. Class 4 cards are a better choice for your Zip.
