WHY PODCAST WON'T DOWNLOAD TO ITUNES

I have a 3rd generation ipod. I been using itunes for a while and all of the sudden is stop working. I can see the ipod connected but when I click to download the podcast to itunes to sync to my ipod I get what it looks like an i.....I right click and look to update podcast again, its start but it stop within 2 second.

What is wrong.......I been trying to figure it out but can't.

Can someone help me........

Thank you