Thank you for visiting Apple Support Communities.
If the media is still located on your computer, I would create a version specifically for the iPad. To create and iPad version in iTunes 11 select the media that you are wanting to convert. From there, select the File menu > Create New Version > Create iPad or Apple TV version. Once the media has been converted, sync the iPad version to the iPad.
I finally came upon the solution to the problem. Aparently when you begin to download an episode or more and something goes wrong, you just can´t pick up where you left off and continue the download. You'll keep on getting the same error message. Simply DELETE that particular episode that appears as started on your iPad but that refuses to download and ask for the download again. That's what I did and it worked perfectly!