Just a quick question... I've noticed that some of the songs I'm listening to with my 5G 30 gig sound considerably distorted.... especially those in the "rock" genre. I'm using Grado SR 80s, and I'm only turning the volume up to about 65-70 percent. In fact, the distortion seems to be there (particularly at loud or intense parts of the song) at any volume level. Could it be the headphones, the ipod, itunes, or MP3's in general? Any input would be appreciated!