Music folder not populated on internal memory but is on external

Hmm, that interesting- the usb transfer mode issue is odd to say the least; what is interesting is that the files are not visible even with both hidden and protected system files visible; a neat trick.  But, I was toggling through all 3 modes and things were definitely buggy. Since it also changed the presentation layer in Win Explorer so that it appeared as a single device rather than two, and fixed the sync bug in Media Player as well as making files visible I’m going to say it was a firmware bug fix.  That’s my story and I’m sticking to it! 

Thanks.