Here is a workaround to be able to resume your downloads:
- Grab the download URL of the video you're watching using sites such as clipnabber.com. Don't close the window after!
- Download the files using the Orbit Downloader.
- When the download fails or when you can't resume it, repeat step number 1. Copy the new download URL.
- Right-click your download in the Orbit Downloader and click "Edit Property..."
- Click the "Mirror" tab and add the new URL.
- Click OK and start the download again!