Thanks for this explanation.
It makes sense, allthough i am running the 8 GB modules in the xw8400 for more than 24 hours with memtest and no error, maybe something with the memory controller is causing this problem.
I have a second xw8400 and maybe it has a newer controller chipset. Than i will test, if that makes a difference.
Also i try to get a used xw8600 as it supports 64 GB and maybe it works with this computer.
Thx for this solution...
G.
