For songs downloaded from emusic.com I'm not able to synch them to my Gen2 Ipod touch. When I try to do that I get 'Itunes could not copy "song title" to the ipod "ipod name" because an unknown error occurred (-50)'
I don't know how to fix it but I know how to get around it. Copy the error song's files to a USB. Once the error songs are on the USB, drag those songs straight to your iPod from the USB. From the USB files to your iPod that should be connected to iTunes. It worked for me. Hope this helps!