I once connected my phone with an SD card to an old kind of computer. I didn't transfer anything, only to charge the phone. But when I disconnected, everything on the SD card was gone, but it still said that files are there. When I connected to another computer, it showed that somehow there was a shortcut of my drive in my own drive. That's why my phone couldn't read it. I solved that problem by formatting the drive and copy everything back. But this time it happened on my iPod, which is more complicate than the last one (and there is 10GB data which is a pain to copy everything all over again).
In conclusion, everything is there (because the iPod says so and I can open files on a computer). But the phone/the iPod can't show/read it, which makes everything worthless. Can someone please tell me how to put the files back to its original place?