songs cutting off then freezing

i downloaded some songs last night using my windows media, which i have never had a problem with before.  listening to the device today, i noticed more than one song would abruptly cut off and then it would just freeze completely.  i would get it to cut off when i’d hold the on/off button for 15 seconds or so and it would come back on normally.  it would happen again if i tried to replay them, so i had to delete them - through windows media - the player wouldn’t even let me delete.  i downloaded the songs from old cd’s, so i didn’t know if that had anything to do with it or not.  can anyone tell why this happens and what i can do to prevent it? this is the first time i’ve ever had any kind of problem with my sansa. 

It might be a tag problem. Use good tag editor like mp3Tag, and make sure you tags are ID3V2.3 ISO8859-1.

If you have copies of the files on the player also on your pc, you could format the player using the player’s menu(settings, system setttings, format), then reconnect the player and reload the songs. You could also try downloading the firmware and manually reinstalling it. Remember after reloading the firmware you need to reset the usb mode to what it was before.

http://www.mp3tag.de/en/

What is the format and bitrate of the files?