I too have the same problem with Sandisk SDXC 64GB memory card like the post by MORTALLKOMBAT.
I’m sick with it now. It manifests strange problems…I take pictures and few minutes to few days later, the new pictures I took is gone. Or the pictures I took 99% of the images are grayed out. I got so angry, I formatted it using the phone formatter.
Happy thinking some inconsitencies cause the proboblems are gone after formatting…NOOOOOOOO!!! Pictures are gone again. I am in the last leg of my vacation. I took bunch of pictures and they are GONE!!! Only old pictures dates back 1/20/2015 are hanging around. Get this!!! AFTER FORMATTING, NEW PICTURES ARE GONE AND OLD PICTURES COME BACK!!! HOW IS THAT PISSIBLE!!!
I’ve been fighting this problem since 1/20/2015. Now 3/25/2015. I lost the pictures over 2 months worth. Vacation pictures/videos gone!!!
I also formatted the card using Win7 with USB connected. After restarting the phone, new pics gone and old pics come back.
The card is around 1/2 full. WTF SANDISK!!! Even if Sandisk replaces with new one, I’m afraid to have the same problem!!! You know???