well, that explains it...

Aha! Audioblog can only take files up to 10MB at a time. Took a bit of doing to run across that information. I guess in the interest of customer service (and podcasty enclosure excuses maybe), instead of telling you your file is too big, they just smush it for you beyond recognition. That's nice of them. It was also nice of them to give me that 7-day trial period, because I'll be outta there very soon.
So I kind of had to go back to where I was about 24 hours ago literally and figuratively. (I'm in the same exact chair I was when this fun started.) Now I have the flash key, but this computer won't read it. Still, my old pal xdrive may yet save the day. More super-exciting updates to come...yawn...