OSX 10.4.8 and the green iSight...
After I was greeted with a wonderful green screen on launching photobooth on my MacBookPro this evening, I noticed with relative shock the sheer number of people with a problem after applying 10.4.8, and so few solutions.. So after several unsuccessful reboots, I finally caved to this suggestion,and reset the PMU on my MBP:

Reset PMU on the MacBook, MacBook Pro

1. If the computer is on, turn it off.2. Disconnect the AC Adapter and remove the computer's battery.3. Press and hold down the power button for 5 seconds and then release the button.4. Reconnect the battery and AC Adapter.5. Press the Power button to restart the computer.

iSight back so far. Time will only tell if it sticks..