Bem, esse tipo de erro parece bem documentado :
A Machine Check Exception (MCE) is a type of computer hardware error that
occurs when a computer's central processing unit detects a hardware problem.
[...] On Linux, a process (such as klogd) writes a message to the kernel log
and/or the console screen (usually only to the console when the error is
non-recoverable and the machine crashes as a result).
As causas desse erro são muito vagas, mas a página da Wikipédia pode ajudar.