QTKit didn't find any attached Video Input Devices!

edit

The following error occurs whenever I try to run a simple application to grab frames from the camera of a Macbook Pro 13" (built-in iSight):

QTKit didn't find any attached Video Input Devices!
Warning, camera failed to properly initialize!
Cleaned up camera.

I've tried passing -1, 0, 1 and other values as parameters to cvCreateCameraCapture() and none worked. It's important to say that I used OpenCV 2.3.1 on this machine for quite a while and it worked fine passing -1 as parameter.

This problem seems to happen with OpenCV v2.4.2 and v2.4.3 on Mac OS X 10.7.5.

Any ideas?