LG V VX-9800

I am not sure if this was covered in a previous thread, but I just got a 1 gig mini SD card. I formatted the card in the phone, then put some mp3s on it. When I put the mini SD card back into my VX9800 and go to my MP3s it says no songs found in memory card. Can someone please tell me where I am going wrong? Also, I used Windows media player to sync with my memory card reader and when I do this, it creates a new folder called music to go along with the four folders already created when the mini SD card was formatted by the phone. Someone please help me. Thanks in advance.