I have this same problem? Do you know the answer?
Well, I DO have an answer!!!! RTFM!!!!! j/k
Seriously, you need to chmod the USB device file for the camera. You'll need to look in /proc/bus/usb for some directories containing device files for your attached USB devices. You will see directories with names like "001" and "002", etc. You will have to change the permissions on the right file to 666 and you should be able to access your camera correctly.
I can't guide you any better than that since I just realized I have USB problems of my own I need to deal with but if you start in /proc/bux/usb, you're going in the right direction.
Peace...