Tim, try this. Open the Animation control window, go down to where it says shadowlit cameras 1 to whatever. Select them all beginning at the first frame and going to the last frame of the animation. While these frames are selected click on the keyframe minus button to remove all key frames and then click on the constant section button. This will clear the shadowlit cameras. Now render the avi again. If that fixed the problem, okay. If not, then you will need to do as Jeff mentioned and contact Curiouslabs about it. Regards, Rob