[ideasrule]

The story behind this is interesting. Patrick suggested using the developer account to test the camera feed. By chance, I was busy doing something and couldn't tell him he was being stupid because I'd already tried that (which I did). By chance, I had changed the image resolution from 640x480 to 320x240. Against all odds, these two unlikely events happened at the same time and led to our strange discovery. (I changed the resolution back to 640x480 and the lag time became the familiar 1/2 s.)

Another possibly useful piece of info is that I was using the code to test the frame rate by measuring the time it took to get 300 fresh images. We got 5 fps on 640x480, 21 fps on 320x240, and 30 fps on 160x120. However, the live feed was certainly not operating at 5 fps at a resolution of 640x480, regardless of the account used. It always operated at 2 fps.