iTunes won't download my purchases

So, as of this past Tuesday, my iTunes doesn't seem to want to download any of my purchases anymore. At first, it was just one song that I had bought that day, so I thought maybe it was just that song and didn't really worry about it. But now that it is the weekend and some of my subscriptions, like Season Pass and a podcast, are starting to download their new entries, I'm starting to see that iTunes doesn't want to download anything. I even bought a random song just to check and, yep, nothing. I just keep getting Error -3259. Now, I've tried restarting iTunes, not allowing for simultaneous downloads, and even reinstalled iTunes to see if any of that would help. It didn't.
What's strange is that even though iTunes won't download video/music/podcasts, it will download/update my iPhone apps just fine, no problem (which is how I know there isn't a problem with my internet or iTunes' connection to it). Any suggestions on how to remedy this issue?