Q:

Webcam: libv4l2 & VIDIOC_DQBUF : No such device

I have written a python code by using OpenCV library to detect a motion. If a motion occurs, it takes a snapshot of the moving object. However my problem is this: If I execute the program on my PC (Ubuntu 12.04) everything's OK.
But when I execute the program on my BeagleBone which has Angstrom Linux running and an Us Robotics webcam device attached to it, after a while it gives the following error: 
libv4l2: error dequeuing buf: No such device
VIDIOC_DQBUF: No such device

How can I solve this problem?
Regards
edit: I installed ubuntu 12.04 to my BeagleBone and everything is OK with it too. It seems like my problem is related to Angstrom image. Maybe a driver or a library (libv4l2?) problem? Any ideas?

A:

I was seeing this error with Ubuntu also when the board was powered through the USB cable.  When I powered the board with a 5V supply, the problem went away.

