I have 2 Fire-i cameras chained together with a 30 ft cable and a firewire hub self-powered. It seems that the cameras are very sensitive to fluctuation of electrical power. Sometimes its fine and sometimes the cameras stop after 30 minutes. It depends in the electrical environnement. I’m looking for the specs of DC adapters that I could plug on each cameras. I have looked on Unibrain site and haven’t found the answer.