Camera Woes

I spent hours last night trying to get the camera control to be able to take a movie via a usb signal. Looks like CHDK cannot do it. However SDM can, in fact sdm looks perfect - its specifically made to make such tasks easy so you can put a camera on a kite. However when I try and boot the sdm software the camera comes up only for a few seconds and then shuts right back down....arrrgh. I've posted my problems on the sdm news group, so hopefully somebody may be able to help me. One user says it works fine with his SD750 - it may be an issue with my canon firmware (which is old) however I see no updates on the canon web site to update the firmware.....