NORVILLE  Lostify is actually working as designed; the problem is the terminology used by iTunes. There are two different "episode number" tags that Lostify can set in your MP4 files: "tven" and "tves". Both are episode numbers, but "tven" is a text string, and "tves" is a plain number.

The "tven" tag is used to store a text string that most TV-oriented websites (like TV.com) refer to as the Production number. It usually has reference to the order in which the episodes were produced, but does not necessarily correspond to the broadcast order. Sometimes it is a 3 or 4 digit number, and sometimes it has an alphabetic prefix and/or suffix. This is why Lostify currently labels it as the "Production #". However, iTunes displays the contents of this tag in the "Episode #" column or field.

The "tves" tag contains only a number. It is probably used internally by iTunes to order episodes within a season (I'm not sure about that), but it is never displayed directly in the user interface as far as I know. I believe it refers to the episode's sequence (as aired) in its given season. Lostify currently labels this field "Episode".

I agree the labelling is confusing. In the next version, if I changed "tven" to be "Episode/Production #", and "tves" to be "Sequence #", would that help?  
(Version 0.3.2)

NORVILLE  This is the way Lostify works by default, because this is the way AtomicParsley (on which Lostify is based) works. Both products are only beta software -- they are not tested completely, and while they work as claimed the vast majority of the time, it is possible you may encounter situations where the output is corrupt, invalid or otherwise bad. If Lostify always overwrote the original video, this type of thing would be a big problem. That's why we always save the result to a new file.

Once things have been tested more and we're fairly confident that the output will never be corrupt, I will add a feature to Lostify so you can optionally overwrite the original.  
(Version 0.2.1)

NORVILLE  Jedik-- I'm not sure what might be going wrong on your file. When something goes wrong, this early alpha build doesn't yet report what it was that didn't work. Version 0.2 will have better error reporting. In the mean time, if you're comfortable with the command line, I could give you some things to try (using AtomicParsley, the command line tool on which Lostify is based) that would give us a good idea what is wrong.

And for everyone else... I have received quite a number of emails from people for whom Lostify has worked fine. Seems none of them have reviewed it here yet, though. :-)

I think it's safe to say that there are some MP4 files out there that don't like to be tagged (or retagged) with Lostify and/or AtomicParsley, but many (for instance, files fresh out of Handbrake or ffmpegX) seem to work just fine.  
(Version 0.1.4)