Sony Mp3 Player

[gibson man]

I've been using windows media player to copy cd's and transfer them to my Sony NWA 1000 player with no problems.
Last few cd's i've tried to copy do not appear on the player even though media player software says copy is complete.
If i access g drive the files are shown.
What's happened?

 

[JohnT93]

maybe the latest files you have uploaded cannot be read by the mp3 (wrong format)