5by5 podcasts not showing in iTunes on my iPhone

Dan and company,
First let me say thank you for putting out a great bunch of podcasts. I discovered you after having eye surgery in January after which I had to spend a week in bed looking down at the floor. You're podcasts kept my mind occupied and kept me from climbing the walls. I've been an avid listener ever since.
On to my problem. For the last several weeks I have been unable to download any of your podcasts (at least, Hypercritical, Back to Work, The Talk Show and Build and Analyze which are the ones I subscribe to) from within iTunes on my iPhone 3G. I can get them from iTunes on my PC and sync, but I generally only sync my phone every few months to either change out the music, or check for software updates. What happens is that when I hit "Get More Episodes..." in iPod it launches iTunes, goes to that show, and it's blank. No past or new episodes, only the title and reviews. I believe this began right around the time that Mac Power Users came aboard. I remember that because since I could not get any of my usual fare, I was browsing all 5by5 and saw the new show. I was in fact able to download both their last show prior to becoming part of 5by5 and the first show on 5by5, however that show has also since gone blank. I've done everything I can think of to correct the problem. I'm running the most recent available version of iOS and I've rebooted the phone repeatedly (yeah, I come from the Windows world where that solves most problems ;-) Please help if you can.
Kind regards, keep up the great work,
PhoenixMylo