I know why. Sorry but I have 3 Sony HandyCams, and the reason is that the CODEC for the voice/image is NOT standard. Do a search on Sony movie editing problem http://realiventblog.com/2006/11/29/tutorials-for-video-editing-with-windows-movie-maker-step-1-import/ http://www.windowsmoviemakers.net/PapaJohn/53/Converting-MPEG.aspx
Q. Why doesn't Movie Maker recognize my Sony MicroMV video camera?
A. Sony MicroMV video cameras record and put out video in the MPEG-2 video format, which unfortunately cannot be captured in Movie Maker.
To work around this issue, do one of the following
• Use the software that came with your Sony MicroMV video camera to capture video from the camera, and then import the resulting video file into Movie Maker.
• Connect your Sony MicroMV camera to your computer using an analog connection, such as an S-video cable or RCA cable, and then capture the video using Movie Maker.