OpenCV in iOS not decoding frames properly - iphone

Question

I'm trying to use OpenCV on iOS to do some pixel analysis on video frames. I've tried several .MOV files (all MPEG-4 AVC) but none of them seem to decode properly.
Problems:
- All cvGetCaptureProperty calls return a value of 1
- cvGrabFrame(capture) always returns true (it doesn't seem to find the last frame)
Things that are actually working
- Frame height and width are correctly determined
Any ideas? I have OpenCV 2.3.2 from http://aptogo.co.uk/2011/09/opencv-framework-for-ios/
NSURL *file = [[NSBundle mainBundle] URLForResource:#"sky" withExtension:#"MOV"];
CvCapture* capture = cvCaptureFromFile([[file path] UTF8String]);
if (!capture)
{
NSLog(#"Error loading file");
return;
}
cvQueryFrame(capture);
int width = cvGetCaptureProperty(capture, CV_CAP_PROP_FRAME_WIDTH);
int height = cvGetCaptureProperty(capture, CV_CAP_PROP_FRAME_HEIGHT);
NSLog(#"dimensions = %dx%d", width, height); // returns 1x1
double framesPerSecond = cvGetCaptureProperty(capture, CV_CAP_PROP_FPS);
NSLog(#"framesPerSecond = %f", framesPerSecond); // returns 1
int frameCount = (int)cvGetCaptureProperty(capture, CV_CAP_PROP_FRAME_COUNT);
NSLog(#"frameCount = %d", frameCount); // returns 1
int frameCounter = 0;
while (cvGrabFrame(capture))
{
frameCounter++;
//NSLog(#"got a frame! %d", frameCounter);
if (frameCounter % 50 == 0)
{
IplImage* frame = cvRetrieveFrame(capture);
NSLog(#"frame width: %d", frame->width); // works correctly
NSLog(#"frame height: %d", frame->height); // works correctly
}
if (frameCounter > 1000)
break; // this is here because the loop never stops on its own
}
cvReleaseCapture(&capture);