The episode is HD with captions and I got a pre-owned first generation iPod Touch with iOS 3.1.3. I've looked around and the Internet says it can't play HD episodes, but I don't know how to get one that's not if that's all I have to do to fix this.
iTunes: May be unable to transfer videos to iPhone, iPad, or iPod
iTunes: Frequently asked questions about viewing and syncing videos
As described, you wil have to download the SD version. Only the 4G and later can play/sync HD videos
Retrieving data ...