Recently many of the videos off the SD have been unplayable, though the cached videos on the mobile device were OK. Would this be due to a hardware malfunction on the Spark or would it more likely be a bad SD card? This is the Samsung SD card that came with the Spark. I tried reformatting the card, but still get many bad videos. I have high respect for Samsung products, though several years ago I bought a couple of bad Samsung SD cards through Amazon. Several reviews claimed these cards were counterfit, though the packaging looked authentic.