Have you looked at these:
You may have to redownload the SD version and sync.
All HD purchases from the iTunes Store also include an iPod/iPhone-compatible Standard Definition version to accompany the HD version. When syncing an HD purchase from the iTunes Store, iTunes will automatically sync the SD video for devices that require SD content.<<
i do not have an SD version - at least one doesn't show up in my itunes.
if i click on SD version in the store, it wants me to buy it.
didn't the store used to say when you looked at an item that you had already purchased it. i.e. the HD version?
so i looked at >>
- Navigate to your Purchased page. Find it by clicking Movies or TV Shows from the top navigation bar in the iTunes Store, and then click Purchased from "QUICK LINKS" in the iTunes Store.
- Choose the appropriate video type: Movies or TV Shows.
- In the lower-right corner of the screen, deselect the box next to "Download HD When Available."
- Search for the desired video and click the download button.
- This should download the standard definition version to your computer so you can sync to your device.<<
trying this now ...