Maybe the new mp3 files are corrupted to begin with.
harry@misohorny1:~$ cd Music
mp3 stream Streaming
harry@misohorny1:~/Music$ cd mp3
Acid Drinkers - Seek And Destroy Studio Version.mp3
ZZ Ward Til the Casket Drops - Pretty Little Liars.mp3
None of mine end up corrupted on my RCA MP3 player
or my BlackBerry Phone
But I use rox file manager or thunar or spacefm. Not KDE Dolphin file manager which to me seems way more bigger than what I use. I bet those files may be no good. My mp4 files transfer fine also on both pieces of hardware mentioned above.