iPod Classic freezes

I have the same/similar problem. New 160gb iPod classic to replace one with dead hard drive. Took 5 days to load all my music onto new device in part because iTunes kept going to sleep...argh!. Now after only a few hours of use, the iPod will either freeze or reset when I select a song to play. Happens in all categories accessing full content of the iPod and paylists with lots of songs. Small playlists seem to play fine after unit resets. BTW.. 32,000 songs on iPod. Largest playlist with 30,700 songs. Main playlist (normally random play) 28,000 songs. The old (dead) iPod classic did not have this problem. Frustrated.