camera black screen in opencv2.2 (Bug #750)

Hi,
when I run my program compiled under codeblocks 10.5 which is designed to display the camera, there is a black screen that appears, here's the code:

#include <opencv2/highgui/highgui.hpp>
#include <iostream>

using namespace std ;

int main (int argc, char * argv[]) {
CvCapture * capture1= cvCreateCameraCapture(0);
CvCapture * capture2= cvCreateCameraCapture(1);
IplImage * img1= NULL ;
IplImage * img2= NULL ;
cvNamedWindow("cam1");
cvNamedWindow("cam2");

while(1)
{
        img1= cvQueryFrame(capture1);
        img2= cvQueryFrame(capture2);
        cvShowImage("cam1",img1);
        cvShowImage("cam2",img2);
cvWaitKey(15);
    }

return 0;
}