Doug Kanter:

On the OTHER hand (and there's always another hand), the machine is
running flawlessly today.....so far. I made just ONE change with the
current module - something that did NOT make any difference with the
Kingston units: Moved the module to the other slot. I'm going to
continue looking for solutions, in case this fails.

Just my opinion but I think you have a hardware problem, if still under
warranty, contact Sony and bug them to fix it.
--
Mac Cool