help with a system freeze

[Seaman]

Freezes of this kind is usually caused by a computer with alot of
hardware devices and a PSU with low effect, but since your computer is
built by IBM it is probably not the case with your computer.

May I ask why you blacklisted ipv6? Try to un-blacklist ipv6 in
"/etc/modprobe.d/blacklist" and see if you notice any different. Just
add a # in front of "blacklist ipv6". Like this;
*#blacklist ipv6*


-- 
Seaman