First make sure you have no conflicts with a firewall or antivirus by disabling them and then trying to download your songs. If you can download with a firewall disabled then set your firewall to allow access to iTunes by following this artical
So I should disable the firewall? I'm just checking because the problem is only happening when I check for purchased music, otherwise I can download music fine and videos about half of the time
Oh OK I thought you couldn't download at all and was using "Check For Purchases" to get songs you have bought. Long has you have bought the songs AND downloaded them completly, you won't have any downloads go when you check for purchases
okay, that one has to be handled at the Music Store end of things. i think the form on this page is the best one to use to report the problem (be sure to mention the error code 0xFFFE7958):