This empeg has shown signs of the drive going bad (hanging on booting), so I'm assuming this error has something to do with a bad drive
Yes, if your player has been showing signs of disk trouble, that would be my first guess as to the reason specific songs are causing errors on download.
Relevant stuff to try:
Diagnosing disk troubleChecking the hard disk for sector errorsPerforming a file system checkRebuilding the music databaseAnother thing to look at is to see if there is any kind of unusual garbage in the songs' tags, stuff like special non-DOS characters, or unusually large comment tags, that sort of thing.
Finally, it might be worth trying to download those songs with Jemplode or with Hijack's FTP or HTTP interfaces, to rule out issues with player/emplode interaction.