Sorry for a few days with no post. It's because I was waiting for a new card. I decided to try it one last time. I bought 32GB ADATA microSD card. And everything is o'k'. I have no problems so propably FiiO is right that sometimes troubles are made by wrong microSD card.

I tried 8GB microSD card yesterday and everything was o'k'. FiiO played all folders. Does it mean that 32GB TF Card is too large ( I used two32GB cards: SanDisk and Kingston)? I don't know if I should give my X3 back to dealer? 

Hello!  Sorry for my not too good english. I bought FiiO X3 in  December (in Poland). I have the same problem as atwaterkent. I've used two different 32GB microSD cards (Kingston and ScanDisk). I've made everything written on FiiO www site...