windows media center error

[I <3 Iaudio9]

so i have been trying to use windows media center to transfer all my songs on to my I9 and i keep getting an error that says, "error occurred while copying this file" on half of my music in my windows media center library. i have the device set to the MTP usb mode. a weird thing is that the files were once on the player but when i tried syncing it to the windows media center again the were no longer on my player. is there something i need to do to get them back or is this an issue with windows? o i am also using windows 7 btw. thanks for the help :)

[I <3 Iaudio9]

i reinstalled the 1.14 firmware and the problem still exists not sure what else to try :[

[I <3 Iaudio9]

im just gonna use winamp, seems to work great so far. do u guys think it is worth pay 20 dollars to be able to use mp3 format?