Update 2015: I've given up trying to fix this, the show is now available at a new URL:
I've figured out why some iTunes users have been reporting problems with subscribing to the Rubenerd Show through the iTunes Store. I deleted my own subscription, searched for "Rubenerd Show" in the iTunes Store and resubscribed to only be given a small circle and an exclamation point.
When I right clicked and chose "Show Description" I was given the above dialog box. No wonder it isn't working, it's trying to access new shows from http:///show/feed/ for some reason!
I don't know how or why this happened. I'll be contacting Apple about this to see if I can get it pointing back to the proper URI again. I believe my good friend Felix Tanjono submitted my podcast to the iTunes Store back in 2005 back when Australia and Singapore didn't have access to it.
While I'm sorting this out you can still go to iTunes, choose the Advanced menu and click Subscribe to Podcast, then enter the following address as a stopgap:
Sorry about this, I don't know how this could have happened :-(.