I can't get any media files loaded on my 64 gb sd card. I hook it up to my computer, transfer stuff over to the card, and it shows that it's on there afterwards, but when I try to access any of it, whether it's a movie or a music file, it's GONE. It will go onto the card if I remove it and put it on directly, but then when I put it back in my Venue, the files are gone. What's going on here, and what can I do about it?