Songs quit playing unexpectedly and jump to another random song–and it occurs in my iTunes library and iPod

Question

     My newly downloaded songs that I purchased a day ago are not playing correctly. The song will start playing, then it will stop at  an odd point (usually the middle of the song) and then skip to another song. And then that newly purchased song will also skip.
     The odd thing is, two out of the thirteen songs that I purchased are fine. They play well, and do not skip at all. Also, the defunct songs do the same thing when I play them in my iTunes library (as well as my iPod nano 5th generation).
     Then, after I had tried the things on the list Troubleshooting Songs That Skip, still the same thing happened. When I tried to sync the songs that were not playing correctly into my iPod, and error popped up that said "Some of the items in the iTunes library were not copied to the iPod "___ iPod" because one or more errors occured" and ot the bottom it said "11 total warnings."
     What should I do???

Answer 1

If they play incorrectly in iTunes, you should probably re-download them.  The songs files may have become corrupted during the download. 
(You may also want to check the integrity of your hard drive volume, because data corruption on the hard drive volume can cause corruption of new files being written to the volume.  If you use a Mac, I can provide additional info on how to check.)
To re-download purchased items from the iTunes Store, go to the iTunes Store main screen in iTunes.  Along the right side, under QUICK LINKS, find and click Purchased.  On the Purchased screen, click on Music.  Find the songs with the problem on the listing below.  To the far right of the song name, it will either say "Downloaded" or have a button with cloud symbol.  Note the ones that say "Downloaded."  Since iTunes thinks you already downloaded those songs on that computer, you'll need to delete them from your iTunes library before being able to re-download.
In the iTunes sidebar, click on Music under LIBRARY.  Find the songs that have this problem in your main Music library listing.  Select each of those songs, and hit the Delete key, confirm you really want to delete the file, and chose the option to move the song file to the Trash.
Go back to the Purchased screen.  This time, those songs should show a button with cloud symbol. Click that button to re-download the song "from the cloud."  Hopefully, they won't have the same problem this time.
NOTE:  You can do this with ANY song previously purchased from the iTunes Store using your Apple ID.