well!your ipod is sad because you didn't buy any music from itunes and you have been listening to illegally ripped songs.

The new generation ipods detect the source of music and show happy face when you buy songs online from itunes site and sad face when you download free songs.

Well I have had an ipod mini, ipod nano (2nd generation), and two ipod classics (my first one got stolen from my car) but I have not had problems with anyone of them except for my ipod mini's battery dying (because the girl who sold it to me thru craigslist sold me an ipod with a battery that was almost dead - after that I never bought an used ipod).

I do not know about the sad face problem. I don't think it should stop working just because you did not buy from itunes. I use all my songs/videos from various sources and less than 5% are bought from itunes.

Does your ipod also display a folder icon? If so, this might help. I have not tried it because i have not faced the problem yet.

http://forums.ilounge.com/showthread.php?s=a7dbb9b0d06cae916d706906fde2ae4e&threadid=135673&highlight=replace+hard+drive

Good luck.

the dreaded “Sad Face” icon is not a good sign at all! Its sad set of XX eyes indicate that you've got a problem. Whether the iPod has been dropped accidentally, or, perhaps more worrying, the sad face icon just showed up for no apparent reason, it is definitely something to be concerned about.

The Sad Face Icon usually appears when the disk scan is not able to retrieve the data on the hard disk. A few different things can cause this problem. Accidents, such as dropping the iPod, are one of the main causes. Unfortunately when the Sad Face Icon does appear and the iPod cannot be seen on the source list in iTunes, it usually means that you are going to have to restore your iPod.

http://www.i-pod-info.com/The_iPod_Sad_Face.html