I subscribed to the giant bombcast through Overcasts' search, and that stream has Alt F1, the powerbombcast and the giant bombcast, ad-free I think. (Unfortunately i have no interest in the non-bombcast content, but oh well.)
The feed was fine before, but there was a problem a few days ago with the Bombcast feed that caused this problem. I've sent an e-mail to the developer to see if he knows of a fix. I'll post it here if it's something that has to be done manually.