How to write a video file with OpenCV?

I am trying to write a program to analyze emotional expressions like tears. As part of my tracker I am using OpenCV to record sample videos. Particularly, I am not certain about how to correctly choose FPS (10FPS seems like it ought to work). I am also not sure which Codec I should use on OS X, I have tried all possible CV_FOURCC from here as well but returned the following error:

Stream #0.0: Video: rawvideo, yuv420p, 640x480, q=2-31, 19660 kb/s, 90k tbn, 10 tbc
Assertion failed: (image->imageSize == avpicture_get_size( (PixelFormat)input_pix_fmt, image->width, image->height )), function writeFrame, file /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_ports_graphics_opencv/work/OpenCV-2.2.0/modules/highgui/src/cap_ffmpeg.cpp, line 1085.

Do you all have some working code with cvWriteFrame? Thanks for taking time to look at my problem!

For those interested the entire program is:

#include <cv.h>
#include <cxcore.h>
#include <highgui.h>

int main (int argc, const char * argv[]) 
{
    CvCapture *capture;
    IplImage  *img;
    int       key = 0;
    CvVideoWriter *writer;

    // initialize camera
    capture = cvCaptureFromCAM( 0 );
    // capture = cvCaptureFromAVI("AVIFile");

    // always check
    assert( capture );

    // create a window
    cvNamedWindow( "video", 1 );

    int color = 1; // 0 for black and white

    // get the frame size
    CvSize size = cvSize((int)cvGetCaptureProperty( capture, CV_CAP_PROP_FRAME_WIDTH),(int)cvGetCaptureProperty( capture, CV_CAP_PROP_FRAME_HEIGHT));

    writer = cvCreateVideoWriter(argv[1], -1 , 10 , size, color);

    while( key != 'q' ) {
        // get a frame
        img = cvQueryFrame( capture );

        // always check
        if( !img ) break;

        cvWriteFrame( writer, img );        
        cvShowImage("video", im