About half of my podcasts won't download. They simply have that gray exclamation mark next to them. Upon closer inspection, it seems that almost all of these podcasts are located at feedburner.com. I am unaware why all these "feedburner" podcasts are gone, but from a few Google searches, it seems that nobody else is having this problem. I thought it was my ISP, however I can download these episodes using different software. I want to keep using iTunes, so I'd like to find a solution. I turned off my anti-virus and firewall (temporarily) and it made no difference. It seems the only solution is a problem with iTunes itself. Any thoughts or ideas?