ios file caching - audio loss in video

Hi,

I am having a strange but serious [meaning Priority One - product doesn't work] problem/bug. The app records and writes video using AVAssetWriter similar to the Camera app. Its is stored in the file system [allocated for the app - not camera roll] and the user is able to play back the video, including audio - works properly.

However, if the app is exited and relaunched and the video is opened again for playback, there is no audio, but the video plays correctly. Indeed a strange problem since the recorded video played back correctly with audio after the recording before exiting the app.

It seems like a weird problem and am wondering what kinda caching is done with the iOS file system and how to look into it and why this is impacting the audio buffer only - seems to me if there is anything else wrong, it should not have played back correctly the first time. I can't think of any good way to investigate or isolate the problem. Any help appreciated.

Thanks,

RFS.