A workaround to enable the Volume Logic plugin on Leopard: yay, I can listen to podcasts comfortably again! If it doesn’t work for you, make sure the iTea file was really copied: for some reason the Finder didn’t manage to overwrite it, and I had to make a copy of the Volume Logic plugin on my desktop, edit that, and copy it back over the original.
This is a shareware plugin that some people paid for; no matter what their reasons are for abandoning development, I can’t believe they refuse to post an update for their paying customers when all it takes is replacing a third-party library. Unless Rogue Amoeba charges through the nose for bug fixes to that library, it’s just unacceptable. I’m glad I never got around to buying it (for some reason the demo never expired).