I too am having the same problem.
The Video Experimenter board works great for about 30 seconds then the overlay stops. I put a Serial.print command in the code to spit out the x,y coordinates and they also stop getting spit out after 30 seconds.
I am using the code example to get familiar with the board, but it seams to stop working after 30 seconds. I reset it and it works for 30 more seconds.
The camera I am using is black and white with a composite video out with 720 x 480 lines. Could this be a problem?
I should mention, that I am only trying to track the bright spot, just like the demo code does in the video on the site. I am using a laser as the bright spot. I tried red and green wavelengths with the same result.
New Results:
I just found out that if I unplug the camera input and plug it back in (without resetting the board) the overlay starts working again along with the Serial.print output I put into the code. I guess it must have something to do with the camera.
I will post debug info as I begin to understand what is happening. Anyone with more info, please post. Would love for this to work without major debug.
Thanks,
-Matt