[iTunes] Being served old episodes from TEDs conference subscription

[Michael Prete]

I have subscribed to the TEDs video podcasts through iTunes. Recently,  
when I click on the "Refresh" button, I am offered many episodes from  
the past, most of which I have seen before. This seems to only happen  
with the TEDs subscription, not any others. My expectation is that I  
will only be offered new episodes that I have not downloaded in the  
past. Any insight into what might be the cause of this mild annoyance?

2.0 GHz G5 iMac, OS 10.5.5, iTunes v8.0.1

------------
Michael Prete

More will be revealed.