iSight Camera switching itself on during boot up

It's happened twice now. Yesterday and today. I've booted up my MacBook and the iSight camera light (the one on the right) switches on. I was wondering about it yesterday so I went into Photo Booth and no camera view showed at all. So I switched the MacBook off and rebooted. It was fine after that.

Same thing happened today though. This time, instead of switching off, I decided to reboot, but the camera was on during the whole reboot. The only way to turn it off is to switch the MacBook off.

I've only had the MacBook for 6 weeks and, other than 1 dead pixel on the right hand side which I've tried to fix, it's been fine. Any idea what's causing the camera to come on? Could this be an indication of a bigger problem?

You had to get it replaced? I was hoping not to have to do that. It hasn't happened since those two times, but if it does start happening, and with more frequency then I guess I will have to call for a replacement. Thanks for the info though.