When I first installed CamSource (2.5) on my iMac (running 10.7.4) and was messing with it a little it was fine, then I closed the main window (app still running in the menu bar) - a while later I noticed CPU meter pegged. Opened Activity Monitor and CamSource was using 90% CPU (motion detection was not on). So I quit CamSource all together and re-started it. When it's just sitting in the menu bar it's fine and when in the menu bar and cams are started I haven't seen a repeat of the high CPU use so far.