Syncing tv shows and movies to my ipod?

I have a problem. I downloaded tv shows from the itunes store and I want to sync it to my ipod now but it doesn't work. I went to the tv shows tab checked sync all unwatched and below that i also checked all tv shows then I clicked apply but this pop up comes up and says the ipod "John" cannot be synced. The required disk cannot be found. What does this mean? I don't understand. I really need some help.

Syncing tv shows and movies to my ipod?
Which iPod do you have? Only certain ones are capable of playing video. It has to be a 5th generation iPod, the new iPod Classic, a 3rd generation iPod Nano, or an iPod Touch. Anything else is incapable of playing video. If you do have one of those models, check out Apple's support pages at:http://www.apple.com/support/ They are very informative.