Songs by some artists simply freeze after a time, then flip to the next track where the same thing happens again

Many iPod forums refer to this problem but I've yet to see an answer!

With tracks from some artists (yes, it afftects whole albums by specific artists), every track will freeze at the same point. There's then a pause whilst the iPod does who-knows-what and it will progress to the next track only for the same thing to happen again.

Sometimes it's with tracks ripped from CD (and so can be restored) and on others it with iTunes downloads. Is it possible to re-download material that one has paid for before because it's corrupted?

The iPod is a 5th generation. The OS is Windows 7.

I have 2 iPods of the same style and the problem can be reproduced on both, so I don't think that it's an iPod hardware issue.

Playing the tracks via iTunes does not produce the problem.

Any thoughts?? There must be a simple answer to this.