Yeah I did.. hmm. I'm downloading it again through iTunes Podcasts now.
Edit: Nope still same problem. I have a theory on why this is happening though: Apple caches data using an external service to local datacenters and ISPs (Akamai), and the cached data I receive based on my location (Auckland, New Zealand) is corrupted. I may have to download it through a proxy in the US.
Edit2: Ah yes, no wonder. I'm now downloading from a server that I have in the US, the filesize is 705MB, compared to 224MB (which is way too small) when I download with my IP based in NZ.