Wow, what an unnecessarily long thread. I had the very same problem as the OP and the question could have easily been answered in one reply without any arguing.
the fiend wrote:
Well - originally, what I was actually trying to do was help the original poster with what appeared to be a Podcast probelm. But we all now know that it is not a Podcast problem at all. It's a question of adding information to the correct fields so that when someone re-labels an MP3 as a Podcast, they can still find it.
I then attempted to clairfy, for anyone who may read this post, exactly what consitutues a Podcast so that they may solve their Podcast problems. (Silly me, obviously! Excuse me for trying to help people.)
The fiend, the problem was that you weren't being helpful. You were being arugmentative and trying to school everybody with your knowledge of how Podcasts actually work. The problem was stated simply.
"I add a Podcast to music, change the type to Podcast, and it disappears?"
Giving a helpful answer while perhaps including a simple explanation of the difference between the file the OP was dealing with and a proper Podcast would be fine. But to act like you can't possibly address the question until you get a satisfactory answer about why the OP would dream of changing the type to Podcast and demonstrate they understand the innerworkings of Podcasts is very unhelpful and, I'd say, rather disingenuous. Since you know this much about Podcasts, you clearly must have been able to understand what was going on.
The OP quite clearly wanted the thing to not disappear and wanted it to be organized as a Podcast with the other Podcasts in his/her library. Anybody with two brain cells to rub together would expect changing the type from Music to Podcast would cause the file to move from the Music category to the Podcast category. In fact, once the disappearing problem is fixed, this is exactly what happens!
Here's an example of what a helpful answer might have been from the very beginning that could have been added in a single post:
"I don't know why the file disappears, perhaps it's a bug in iTunes, but here's how to fix it. iTunes seems to have a problem with certain characters in a Podcast name that can cause it to disappear. Change the name to something very simple that doesn't have periods(.), dashes(-), or anything like that. Once you've done this, change the type to Podcast and you should then see it organized with your other Podcasts.
By the way, the file you downloaded isn't technically a Podcast. <And now let me tell you all of the technical details about Podcasts you probably don't need or want to know....>"
There. Done.
This fixed my problem and it didn't require a lecture about Podcasts.