I really want to like these and I do trust SanDisk more than other manufacturers of memory cards. That said, I'm moving on to my 3rd card. Thank you Amazon for having exceptional customer service, or else I'd be very upset.Basically this card will suddenly not allow writing to it anymore. You can't save files to it, you can't delete files from it and you can't event format it. I've tried doing all three in different OS'es and devices with no luck. Doing some reading on the SanDisk forums this seems to be happening a lot with these cards.I'm returning this to Amazon and trying my luck with a different brand to see what happens.