Well, I'd like to call it a bug, but it was just my stupidity.
Apparently the XML feed never referenced the enclosure for episode 33, but it pointed to episode 32 instead. I don't know how I missed it, but I did. Never the less, the feed has been updated.
Hopefully this won't screw up iTunes too badly.
My sincere apologies.
[UPDATE] - I just checked my iTunes, and it downloaded the correct podcast. Now I have two entries for episode 33.