Can you give us some specific examples? I'd like to see what you mean but need a show to search for first. Also, a screenshot might be helpful, too.
Each show host is responsible for their individual show feeds, and the management of that feed. We had an issue recently with Mevio suspending some of our shows (long story), but they were supposed to be reinstating them the last I heard. That may be causing the problem, but again, without knowing specifically which show(s) you're referring to, I can only speculate.
The main GaragePunk Pirate Radio feed is still active on iTunes, though:
http://itunes.apple.com/us/podcast/garagepunk-pirate-radio/id488749369
I'll try to get the show hosts involved with this discussion so they can each check their own iTunes listings/feeds.
Cheers,
kopper