If a USB device tries to draw more power than the port can provide, you'd see the sorts of problems you're seeing. It's because the extra current lowers the voltage and that creates problems as the device is sort-of powered and can't communicate coherently to the controller. That tends to make controllers upset and upset hardware combined with the typical writing standard of Windows drivers usually results in an upset Windows.
I'd try the camera with it's external power connected. I'd also try it in all the USB ports, including the ones on the back. It may be a problem with one or two; it may be a problem with the USB controller on the motherboard in general. If it seems isolated to the ones on the front (say), then I'd probably run an extension lead from a socket on the back. In fact, I'd probably find a powered hub (but still connect it to the back). A powered hub may be just as likely to fix the problem, anyway, even if none of the USB ports like your camera, either.
Wade.