One podcast I'm subscribed to wont download one podcast but others before and after will download what can I do?

I'm subscribed to a podcast group and I've never had trouble with it before just one podcast didnt download and now it wont download at all, ones before it and after it will but this one wont, It plays on itunes but thats it. I tried deleting it and re subscribing but it just is downloading I dunno what to do beucase i only get chance to listen to them on mu ipod when I'm out and about I dont have time to listen to them otherwise.

Thanks, Carrie.