The REALLY, REALLY, REALLY important information…
Do NOT have spaces in the podcast file name BEFORE you upload it.
If it does, then WordPress will NOT correctly & automatically generate the necessary enclosure code within your post so that others can successfully subscribe to it. They can still listen to it, though, via the blog posting; just not subscribe to it via iTunes, Yahoo, Juice, or the likes…
There is a work-around that I have successfully used, but when all it takes is to heed my often-heard mantra, “no spaces & all lower case”, why bother!