It has nothing to do with the file system. I just meant that the sound changed a bit with the new FW.
BTW, now I hear a light hiss between songs. And yes, the wrong bitrate infi, if i press the Info icon. But it does not bother me. Something has definately changed with the sound, it might be the placebo effect, though.
The good thing is my 64Gb cards in exFAT work perfectly. So, I've been thinking of getting a 128Gb one, or two:)