I have bought a galaxy s4 and I also got a 64 gb sd card. on the sd card it says "Microsdhc 64 gb."its a class 10. I put it in my phone. and it seems like it works. I put my 25 gb of music on it. it shows up some and rest are all unknown artists. i restart my phone. it says damaged sd card. i format it again. and when i put some music on it its at 59.74 gb. restart my phone it works. if i go past 59.74gb available space it will show up as damaged sd card. can someone please help me. i cant really have 6 damaged 64 gb sd cards.