New playlists freezing on iPod classic. Old playlists are fine.

I recently invested a lot of time putting together two new playlist for the iPod classic that I use for muzak in my shop. The music on these playlists is pretty much new to the iPod. It is mostly from records that I have copied to .mp3. My iPod is an older 30gb model with fully updated software. The playlists that I've put together in the past seem to work fine with only an occasional freeze (maybe once a month). When the iPod freezes I do a reset and all seems fine. These are long playlists with 24hrs of music minimum and they play for at least 8 hours every day. The problem is that the new playlists seem to freeze up every ten minutes or so. I've since given up using them until I figure out what's wrong. I've made two regular playlists and two smart playlists based on them. Both types freeze up constantly.

Again, the older playlists seem to work just fine. By "older" I mean, I put them together a couple of years ago and have been adding music since, with no added problems. Only the playlists that I've created in the last couple of weeks seem to be having this problem. There is nothing different about the way I've gone about putting the lists together. The file formats and bit rates are all the same. The songs that freeze the new playlists work fine in the old playlists and they play just fine on their own and in iTunes. For example, just this morning, five songs into starting the "Lounge" playlist the **** thing froze. The song was something by Bobby Darin. I reset the iPod and scrolled to that particular song . . . it played just fine. So, why are my new playlists causing this problem?

I'm hoping someone might have the answer. I realize that the iPod is quite old and it does get a lot of use so perhaps it's time for a new one . . . but I'd like to keep using it if possible.

If any further information is needed I'd be happy to give it.