is that sound of a creaky door closing when you click repeatedly associated with yahoo messenger or a messenger program?
That appears to happen without being prompted.
I would try disabling any chat software from startup (in msconfig or through the software user preferences / settings).
Once all chat software is disabled let the pc sit idle to emulate the problem. See then if you get the BSOD, if not you have narrowed a possible cause and you can begin to experiment with the settings.
You think the problem may have something to do with the onboard webcam. I would make sure any chat software isn't displaying the webcam for the online world to attempt access, it may be that you are being flooded with requests to view and causing messenger to crash (unable to contact server) and take the OS with it.
This is all a shot in the dark, but that familiar creaky door sound caught my attention.