I am using EyeTV to convert TV recordings for playback on my iPhone. It's a great way to enjoy old TV series, particularly since I use EyeTV to record the over-the-air digital TV signals for free. (See One Week With EyeTV - O'Reilly Digital Media Blog for more about this.)
However, if you use the pre-defined iPhone export setting, and you have an El Gato Turbo.264 encoder stick (which is generally great and makes the export go much, much faster) you may receive a very cryptic error message when converting the video.
El Gato tech support referred me to this support article: When using Turbo.264, some exports to the Apple TV format may fail. The error message I got was (-536870176) and I'm not exporting to AppleTV, so I assumed it didn't apply when I found it before contacting El Gato.
But the advice works in my situation, too. I changed EyeTV to export using the "iPod - Best" preset and this completely resolved the problem. I hope that El Gato will have a fix soon--that support article is six months old--but for now the workaround is just fine. Give it a try if you're having the same problem