If voltage spikes are the cause then why do 65nm chips seem to not suffer from it too much? People put 1.5V+ into 65nm chips so the voltage spikes should be even higher.

You people are all raising the voltage to 1.4V from 1.1V, which is 27% increase of voltage. On 65nm, take an average VID of 1.275V, and 27% increase in voltage translates to 1.62V!