Consecutive calls to startRecordingToOutputFileURL:

In the docs it's stated this:

If a file at the given URL already exists when capturing starts, recording to the new file will fail.

Are you sure you check that nextUrl is a non-existing file name?

Thanks all, for the review and good thoughts on this. Here's the word from Apple DTS...

I spoke with our AV Foundation engineers, and it is definitely a bug in that this method is not doing what the documentation says it should ("You do not need to call stopRecording before calling this method while another recording is in progress."). Please file a bug report using the Apple Bug Reporter (http://developer.apple.com/bugreporter/) so the team can investigate. Make sure and include your minimal project in the report.

I've filed this with Apple as bug 11632087