After much messing around with what appeared to be 4 faulty routers in a row I realized that I can reproduce causing my DLINK DIR-655 router to freeze up and require a hard reboot (to factory setttings) by simply plugging in my Lenovo W520's ethernet card.
I was also able to reproduce this on my old Asus RT-N16. I went through 4 routers (3 Asus and 1 DLink) and can reproduce this.
Does this sound like a possible?