iPod freezes repeatedly

I got a 30GB iPod Video for Xmas this past year (2006) and I've used it nearly every day since. Over the last couple weeks, it has been freezing up on me. For example, on my way to work this morning, it froze somewhere on the first song. It will keep playing, but the screen freezes, no buttons work, and it stops once it finishes the current song. I can manually reset it with the "silde hold switch, hold buttons" method, but that's only a temporary fix.

I've tried resetting the iPod to factory settings and reloading all my music. It doesn't seem to be linked to any one song file, since I have been noting what song it freezes on. It still locks up.

Any ideas, knowledgable Mac people, or does it need to be sent it for repair? Thanks in advance for your help.