hello, I compile the module gspca(for having webcam working) and v4l1-compat for n800. With insmod load correctly, I activate usbhost and I connect the webcam. In /dev/video apears /dev/video1 and /dev/video0. I prove a lot of combinations, deleting /dev/video0 and move /dev/video1 to /dev/video0 and execute software to see webcam , try to execute webcam soft from /dev/video1. But when I execute the program the led of the webcam power on but just 2 seconds left N800 freeze and reboot. I don't understand why, If anyone know what happen or know one solution please told me. Sorry my english.

If the webcam draws more than 100mA of power --- which is almost a given, unless it's externally powered --- it could cause a hardware panic when it goes from low-power inactive to high-power active state.

If you've got a powered hub, that'd be the next step: what model is the webcam?