iphone - CCVideoPlayer play movie finished get Screen flicker,what's wrong with it?

Question

I use CCVideoPlayer to play video. and when video finished the screen sometime get a Screen flicker. it look like the videoView quit animation.

Does someone know what's wrong with it?

- ( void ) moviePlaybackFinished
{
    CCLOG(@ "moviePlaybackFinished" );

    NSString * className =  [PublicApi readSceneClassName];
    id aClass = NSClassFromString(className);
    if(aClass!=nil)
    {
     if([aClass respondsToSelector:@selector(moviePlaybackFinished: ResArr: Menu:      MovieNum:)])
    {

}

self.movieNum++;
} 

- ( void ) movieStartsPlaying
{
    CCLOG(@ "movieStartsPlaying" );
} 

#ifdef __IPHONE_OS_VERSION_MAX_ALLOWED
// Updates orientation of CCVideoPlayer. Called from SharedSources/RootViewController.m
- ( void ) updateOrientationWithOrientation: (UIDeviceOrientation) newOrientation
{
CCLOG(@ "updateOrientationWithOrientation" );
[CCVideoPlayer updateOrientationWithOrientation:newOrientation ];
}
#endif